Avoid access violation in TPythonModule.GetVarAsVariant (see https://en.delphipraxis.net/topic/7085-returning-lists-from-python-to-delphi/)

Author: pyscripter

Source/PythonEngine.pas

@@ -7311,11 +7311,12 @@ function  TPythonModule.GetVarAsVariant( const varName : AnsiString ) : Variant;
   with Engine do
     begin
       obj := GetVar( varName );
-      try
-        Result := PyObjectAsVariant( obj );
-      finally
-        Py_XDecRef(obj);
-      end;
+      if Assigned(obj) then
+        try
+          Result := PyObjectAsVariant( obj );
+        finally
+          Py_XDecRef(obj);
+        end;
     end;
 end;