Fix matlab Faust destructor bug occurring when factors passed are invalid...

Fix matlab Faust destructor bug occurring when factors passed are invalid because of not matching dimensions and hence the Faust object is not really instantiated.

wrapper/matlab/tools/FaustCore.m

@@ -80,10 +80,12 @@ classdef FaustCore < handle
         %% Destructor - Destroy the C++ class instance
         function delete(this)
             % destructor delete the faust
-            if (this.isRealFlag)
-                mexFaustReal('delete', this.objectHandle);
-            else
-                mexFaustCplx('delete', this.objectHandle);
+            if(isa(this.objectHandle, 'integer'))
+                if (this.isRealFlag)
+                    mexFaustReal('delete', this.objectHandle);
+                else
+                    mexFaustCplx('delete', this.objectHandle);
+                end
             end
         end