Properly quote paths for GCC warnings files (#8523)
Properly quote paths for GCC warnings files (#8523)

Fixes issue identified by @jjsuwa-sys3175 in
https://github.com/esp8266/Arduino/commit/46190b61f159bbaa614d046d8b229cd648e9dccc#r69649862
esp8266/Arduino,esp8266/Arduino,sticilface/Arduino,esp8266/Arduino,sticilface/Arduino,sticilface/Arduino,esp8266/Arduino,sticilface/Arduino,sticilface/Arduino,esp8266/Arduino