Improve clarity between is_activated and prohibit_login (#1788)

It used to be unclear what the difference between the two are.

Author: pgaskin

options/locale/locale_en-US.ini

@@ -1134,8 +1134,8 @@ users.update_profile_success = Account profile has been updated.
 users.edit_account = Edit Account
 users.max_repo_creation = Maximum Repository Creation Limit
 users.max_repo_creation_desc = (Set -1 to use global default limit)
-users.is_activated = This account is activated
-users.prohibit_login = This account is prohibited to login
+users.is_activated = This account has completed activation
+users.prohibit_login = This account is blocked from logging in
 users.is_admin = This account has administrator permissions
 users.allow_git_hook = This account has permission to create Git hooks
 users.allow_import_local = This account has permissions to import local repositories