Fix the problem of displaying the user notification message (#63)

Signed-off-by: Jelena Sanko <jelena@raulwalter.com>

Author: jsanko

prefPane/id-updater.m

@@ -155,7 +155,6 @@ - (void)message:(NSString *)message {
         if (center) {
             NSUserNotification *notification = [NSUserNotification new];
             notification.title = NSLocalizedString(@"Update message", nil);
-            notification.subtitle = message;
             notification.informativeText = message;
             notification.soundName = NSUserNotificationDefaultSoundName;
             center.delegate = self;