delete EXCHANGE_OAUTH_ENABLED from conf. Add comment on UT

Signed-off-by: wenyang-cao <wenyang.cao@ibm.com>

Author: wenyang-cao

src/main/resources/exchange.conf

@@ -53,8 +53,6 @@ api {
   tls.password   = ${?EXCHANGE_TLS_PASSWORD}
   tls.truststore = ${?api.tls.truststore}
   tls.truststore = ${?EXCHANGE_TLS_TRUSTSTORE}
-  
-  oauth.enabled  = ${?EXCHANGE_OAUTH_ENABLED}
 }
 
 exchange-db-connection {

src/main/resources/reference.conf

@@ -159,8 +159,6 @@ api {
   tls.password   = null     # Truststore's password
   tls.truststore = null     # Absolute path and name of your pkcs12 (.p12) truststore that contains your tls certificate and private key
 
-  oauth.enabled = false
-
   cache {
     authDbTimeoutSeconds = 15         # Timeout for db access for critical auth info when cache missing
     IAMusersMaxSize      = 300        # The users that are backed by IAM users

src/test/scala/org/openhorizon/exchangeapi/route/user/TestPatchUserRoute.scala

@@ -206,6 +206,12 @@ class TestPatchUserRoute extends AnyFunSuite with BeforeAndAfterAll with BeforeA
     assert(dbUser.modified_by === user.modified_by)
   }
 
+  // Note:
+  // If the environment variable EXCHANGE_OAUTH_USER_INFO_URL is set (via `export`),
+  // the updateConfig(...) call cannot override its value.
+  // This might cause tests that rely on non-OAuth mode to fail.
+  // To ensure consistent behavior, unset the variable before running tests with:
+  // unset EXCHANGE_OAUTH_USER_INFO_URL
   def updateConfig(key: String, value: String): Unit = {
       val configInput = AdminConfigRequest(key, value)
       val response = Http(BASEURL+"/admin/config").postData(Serialization.write(configInput)).method("PUT").headers(CONTENT).headers(ACCEPT).headers(ROOTAUTH).asString

src/test/scala/org/openhorizon/exchangeapi/route/user/TestPostChangeUserPasswordRoute.scala

@@ -190,6 +190,12 @@ class TestPostChangeUserPasswordRoute extends AnyFunSuite with BeforeAndAfterAll
     info("Body: " + response.body)
   }
 
+  // Note:
+  // If the environment variable EXCHANGE_OAUTH_USER_INFO_URL is set (via `export`),
+  // the updateConfig(...) call cannot override its value.
+  // This might cause tests that rely on non-OAuth mode to fail.
+  // To ensure consistent behavior, unset the variable before running tests with:
+  // unset EXCHANGE_OAUTH_USER_INFO_URL
   def updateConfig(key: String, value: String): Unit = {
       val configInput = AdminConfigRequest(key, value)
       val response = Http(BASEURL+"/admin/config").postData(Serialization.write(configInput)).method("PUT").headers(CONTENT).headers(ACCEPT).headers(ROOTAUTH).asString

src/test/scala/org/openhorizon/exchangeapi/route/user/TestPostUserRoute.scala

@@ -165,7 +165,12 @@ class TestPostUserRoute extends AnyFunSuite with BeforeAndAfterAll with BeforeAn
       info("Code: " + response.code)
       info("Body: " + response.body)
   }
-
+  // Note:
+  // If the environment variable EXCHANGE_OAUTH_USER_INFO_URL is set (via `export`),
+  // the updateConfig(...) call cannot override its value.
+  // This might cause tests that rely on non-OAuth mode to fail.
+  // To ensure consistent behavior, unset the variable before running tests with:
+  // unset EXCHANGE_OAUTH_USER_INFO_URL
   def updateConfig(key: String, value: String): Unit = {
       val configInput = AdminConfigRequest(key, value)
       val response = Http(BASEURL+"/admin/config").postData(Serialization.write(configInput)).method("PUT").headers(CONTENT).headers(ACCEPT).headers(ROOTAUTH).asString

src/test/scala/org/openhorizon/exchangeapi/route/user/TestPutUserRoute.scala

@@ -187,7 +187,13 @@ class TestPutUserRoute extends AnyFunSuite with BeforeAndAfterAll with BeforeAnd
     info("Code: " + response.code)
     info("Body: " + response.body)
   }
-
+  
+  // Note:
+  // If the environment variable EXCHANGE_OAUTH_USER_INFO_URL is set (via `export`),
+  // the updateConfig(...) call cannot override its value.
+  // This might cause tests that rely on non-OAuth mode to fail.
+  // To ensure consistent behavior, unset the variable before running tests with:
+  // unset EXCHANGE_OAUTH_USER_INFO_URL
   def updateConfig(key: String, value: String): Unit = {
       val configInput = AdminConfigRequest(key, value)
       val response = Http(BASEURL+"/admin/config").postData(Serialization.write(configInput)).method("PUT").headers(CONTENT).headers(ACCEPT).headers(ROOTAUTH).asString