Fixed YAML indent for login methods (#2676)

Author: mnocon

docs/users/login_methods.md

@@ -20,7 +20,7 @@ security:
         ibexa_username:
             id: ibexa.security.user_provider.username
 
-       ibexa_email:
+        ibexa_email:
             id: ibexa.security.user_provider.email
 
     firewalls:
@@ -54,4 +54,4 @@ For example, to ensure that user names can only contain lowercase letters, set `
 ![Setting a user name pattern](username_pattern.png)
 
 To check that all existing user accounts have names that fit the current pattern, run the `ibexa:user:audit-database` command.
-It checks all user accounts in the database and lists those that don't fit the pattern.
+It checks all user accounts in the database and lists those that don't fit the pattern.