message: Makefile: fix `make clean` on macOS
diff: @@ -147,7 +147,7 @@ distclean:
  @rm -rf logs/
  clean:
  - @if [ -d build ]; then find build -mindepth 2 ! -regex 'build/\w+/third_party.*' -delete; fi
  + @if [ -d build ]; then find build -mindepth 2 ! -regex 'build/[a-zA-Z_]*/third_party.*' -delete; fi
  android_env_check:
  ifndef ANDROID_TOOLCHAIN_CMAKE
  