strip whitespace in docs

docs/change_login.md

@@ -3,7 +3,7 @@
 ## Break your login function
 
 Usually your login function will check for username and password, log the user in if the username and password are correct and create the user session, to support mfa, this has to change
- 
+
  * authenticate the user
  * if username and password are correct , check if the user has mfa or not
      * if user has mfa then redirect to mfa page
@@ -11,13 +11,13 @@ Usually your login function will check for username and password, log the user i
 
 ```python
 def login(request): # this function handles the login form POST
-    user = auth.authenticate(username=username, password=password)  
+    user = auth.authenticate(username=username, password=password)
     if user is not None: # if the user object exist
          from mfa.helpers import has_mfa
          res =  has_mfa(username = username,request=request) # has_mfa returns false or HttpResponseRedirect
          if res:
              return res
-         return log_user_in(request,username=user.username) 
+         return log_user_in(request,username=user.username)
             #log_user_in is a function that handles creatung user session, it should be in the setting file as MFA_CALLBACK
 ```