Fix potential incorrect null checks in FlaxEngine.Objects

The null-conditional operator checks for reference equality of the
Object, but doesn't check the validity of the unmanaged pointer. This
check is corrected in cases where the object was not immediately
returned from the bindings layer and may have been destroyed earlier.

Source/Editor/CustomEditors/Dedicated/ScriptsEditor.cs

@@ -576,8 +576,8 @@ namespace FlaxEditor.CustomEditors.Dedicated
                     return;
                 for (int j = 0; j < e.Length; j++)
                 {
-                    var t1 = scripts[j]?.TypeName;
-                    var t2 = e[j]?.TypeName;
+                    var t1 = scripts[j] != null ? scripts[j].TypeName : null;
+                    var t2 = e[j] != null ? e[j].TypeName : null;
                     if (t1 != t2)
                         return;
                 }