use objExists instead of set exists for animated object set

- set exists will look through a list of sets without the namespace, which may cause issues if there are multiple sets of the same name in different namespaces.

Author: vkovec

Assets/Integrations/Autodesk/maya/scripts/unityCommands.mel

@@ -319,7 +319,7 @@ proc exportSet(string $unitySet, int $exportAnim){
         eval $strCmd;
     }
 
-    if(setExists($animatedObjectSet)){
+    if(`objExists $animatedObjectSet`){
        delete $animatedObjectSet; 
     }
 }