refactor code to match EE changes

lib/gitlab/git_access.rb

@@ -166,7 +166,7 @@ module Gitlab
       end
 
       if Gitlab::Database.read_only?
-        raise UnauthorizedError, ERROR_MESSAGES[:cannot_push_to_read_only]
+        raise UnauthorizedError, push_to_read_only_message
       end
 
       if deploy_key
@@ -280,5 +280,9 @@ module Gitlab
                          UserAccess.new(user, project: project)
                        end
     end
+
+    def push_to_read_only_message
+      ERROR_MESSAGES[:cannot_push_to_read_only]
+    end
   end
 end

lib/gitlab/git_access_wiki.rb

@@ -19,10 +19,14 @@ module Gitlab
       end
 
       if Gitlab::Database.read_only?
-        raise UnauthorizedError, ERROR_MESSAGES[:read_only]
+        raise UnauthorizedError, push_to_read_only_message
       end
 
       true
     end
+
+    def push_to_read_only_message
+      ERROR_MESSAGES[:read_only]
+    end
   end
 end