(fix) small code refactoring

UI/MailerUI/UIxMailListActions.m

@@ -883,7 +883,7 @@
       data = [NSDictionary dictionaryWithObjectsAndKeys:
                              @"No UID specified", @"error", nil];
       return [self responseWithStatus: 404 /* Not Found */
-                                    andString: [data jsonRepresentation]];
+                            andString: [data jsonRepresentation]];
     }
 
   uids = [data objectForKey: @"uids"];

UI/MailerUI/UIxMailMainFrame.m

@@ -124,11 +124,8 @@
   NSString *s;
 
   s = [self mailAccounts];
-  response = [self responseWithStatus: 200];
-
-  [response setHeader: @"text/plain; charset=utf-8"
-               forKey: @"content-type"];
-  [response appendContentString: s];
+  response = [self responseWithStatus: 200
+                            andString: s];
 
   return response;
 }