message: Fix blurred icon app in 10.12
diff: icon = [NSImage imageNamed:@"AppIconActive"];
  break;
  case AppIconTypeDefault :
  - if (@available(macOS 10.12.0, *))
  + if (@available(macOS 10.13.0, *))
  {
  - icon = [NSImage imageNamed:@"AppIcon"];
  + icon = [NSImage imageNamed:@"AppIcon"]; // NSImageNameApplicationIcon causes lost icon app in NSAlert in 10.13+
  } else {
  icon = [NSImage imageNamed:NSImageNameApplicationIcon];
  }
  