fix doc build error

docs/appcontext.rst

@@ -5,14 +5,14 @@ The Application Context
 
 .. versionadded:: 0.9
 
-One of the design ideas behind Flask is that there are at least two 
+One of the design ideas behind Flask is that there are at least two
 different “states” in which code is executed:
 
-1.  The application setup state, in which the application implicitly is 
-on the module level.  
+1.  The application setup state, in which the application implicitly is
+on the module level.
 
-    This state starts when the :class:`Flask` object is instantiated, and 
-    it implicitly ends when the first request comes in.  While the 
+    This state starts when the :class:`Flask` object is instantiated, and
+    it implicitly ends when the first request comes in.  While the
     application is in this state, a few assumptions are true:
 
     -   the programmer can modify the application object safely.
@@ -21,20 +21,20 @@ on the module level.
         modify it, there is no magic proxy that can give you a reference to
         the application object you're currently creating or modifying.
 
-2.  In contrast, in the request handling state, a couple of other rules 
+2.  In contrast, in the request handling state, a couple of other rules
 exist:
 
     -   while a request is active, the context local objects
-    (:data:`flask.request` and others) point to the current request.
+        (:data:`flask.request` and others) point to the current request.
     -   any code can get hold of these objects at any time.
 
-3.  There is also a third state somewhere in between 'module-level' and 
+3.  There is also a third state somewhere in between 'module-level' and
 'request-handling':
 
     Sometimes you are dealing with an application in a way that is similar to
-    how you interact with applications during request handling, but without 
-    there being an active request.  Consider, for instance, that you're 
-    sitting in an interactive Python shell and interacting with the 
+    how you interact with applications during request handling, but without
+    there being an active request.  Consider, for instance, that you're
+    sitting in an interactive Python shell and interacting with the
     application, or a command line application.
 
 The application context is what powers the :data:`~flask.current_app`