fix yml format

Author: v-vasuke

articles/spring-cloud/spring-cloud-tutorial-config-server.md

@@ -157,13 +157,13 @@ If you have written a YAML file with your repository settings, you can import yo
 
 ```yml
 spring:
-        cloud:
-                config:
-                    server:
-                            git:
-                                    uri: https://github.com/azure-spring-cloud-samples/config-server-repository.git
-                                    username: username
-                                    password: password/token
+    cloud:
+        config:
+            server:
+                git:
+                    uri: https://github.com/azure-spring-cloud-samples/config-server-repository.git
+                    username: <username>
+                    password: <password/token>
 
 ```