when configuring mac_package.py for App, BA_PY_MODE must be OFF (#940)

App/CMakeLists.txt

@@ -132,7 +132,8 @@ if(BA_APPLE_BUNDLE)
         )
     # Qt plugins directory in within the MacOS bundle
     set(MACPKG_QT_PLUGINS_DIR PlugIns)  # conform to settings in `qt.conf`
-    # convert CMake list to space-separated lists
+
+    set(BA_PY_MODE "OFF")
     set(MACPKG_EXTRA_LIBS "${BA_Dependencies}")
 
     configure_file("${CMAKE_SOURCE_DIR}/devtools/deploy/mac/mac_package.py.in"