Doc: Fix indentation issue

Old indentation made the :ref: into a literal block, thus not a real
reference. This should do the trick.

doc/sphinx/faq/general.rst

@@ -187,7 +187,7 @@ Yes, you need VCL code like this::
 		set req.backend = foobar;
 	}
 
-    Please see :ref:`tutorial-advanced_backend_servers-directors_`.
+Please see :ref:`tutorial-advanced_backend_servers-directors_`.
 
 
 Why ...