- Fixed another bug that I introduced when CodeQL fixed (NullReferenc…

…eException, handler is null).

I reviewed all the changes related to (someVariable.Equals(someValue)), all of them should be ok.

src/Caliburn.Micro.Platform/Platforms/Maui/ActionMessage.cs

@@ -253,7 +253,8 @@ void OnPropertyChanged(object s, PropertyChangedEventArgs e) {
         public object Handler {
             get => handler;
             private set {
-                if (handler.Equals(value)) {
+                if (handler != null &&
+                    handler.Equals(value)) {
                     return;
                 }