Update Linux CI

Author: koutcher

.github/workflows/linux.yml

@@ -4,7 +4,7 @@ on: [push, pull_request]
 
 jobs:
   ci:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
 
     strategy:
       matrix:

src/keys.c

@@ -111,7 +111,8 @@ del_keybinding(const struct key key[], size_t keys)
 				table->size--;
 				for (; j < table->size; j++)
 					table->data[j] = table->data[j + 1];
-				table->data = realloc(table->data, table->size * sizeof(*table->data));
+				if (table->size)
+					table->data = realloc(table->data, table->size * sizeof(*table->data));
 			}
 	}