Merge pull request pallets#603 from rmacy/patch-1

Fixed typo occours to occurs

Author: Kenneth Reitz

flask/app.py

@@ -1265,7 +1265,7 @@ def handle_user_exception(self, e):
 
     def handle_exception(self, e):
         """Default exception handling that kicks in when an exception
-        occours that is not caught.  In debug mode the exception will
+        occurs that is not caught.  In debug mode the exception will
         be re-raised immediately, otherwise it is logged and the handler
         for a 500 internal server error is used.  If no such handler
         exists, a default 500 internal server error message is displayed.