chore(guide/server-communication): fix indentation in Jade

Author: chalin

public/docs/ts/latest/guide/server-communication.jade

@@ -73,7 +73,7 @@ block system-config-of-http
       SystemJS knows how to load services from the !{_Angular_http_library} when we import from the `@angular/http` module
       because we registered that module name in the `system.config` file.
 :marked
-    Before we can use the `#{_Http}` client , we'll have to register it as a service provider with the Dependency Injection system.
+  Before we can use the `#{_Http}` client , we'll have to register it as a service provider with the Dependency Injection system.
 .l-sub-section
   :marked
     Learn about providers in the [Dependency Injection](dependency-injection.html) chapter.