Adds resource to logging

spring-cloud-config-client/src/main/java/org/springframework/cloud/config/client/ConfigServerConfigDataLoader.java

@@ -159,7 +159,7 @@ public class ConfigServerConfigDataLoader implements ConfigDataLoader<ConfigServ
 			throw new IllegalStateException("Could not locate PropertySource and " + reason + ", failing"
 					+ (errorBody == null ? "" : ": " + errorBody), error);
 		}
-		logger.warn("Could not locate PropertySource: " + (error != null ? error.getMessage() : errorBody));
+		logger.warn("Could not locate PropertySource (" + resource + "): " + (error != null ? error.getMessage() : errorBody));
 		return null;
 	}