Fix sequencing bug

Signed-off-by: Andrew Fiddian-Green <software@whitebear.ch>

Author: andrewfg

bundles/org.openhab.core.io.transport.upnp/src/main/java/org/openhab/core/io/transport/upnp/UpnpDeviceFinder.java

@@ -140,8 +140,8 @@ public void addUDN(UDN udn) {
      * Remove the given UPnP device UDN from the subscriptions list and cancel any pending search.
      */
     public void removeUDN(UDN udn) {
-        subscriptions.remove(udn);
         cancelSearch(udn);
+        subscriptions.remove(udn);
         logger.debug("Removed subscription for {}", udn);
     }