devutils/set_quilt_vars.sh: Add refresh arg --strip-trailing-whitespace
devutils/set_quilt_vars.sh: Add refresh arg --strip-trailing-whitespace

Thanks for the suggestion in https://github.com/Eloston/ungoogled-chromium/pull/1011#issuecomment-618590125

Eloston/ungoogled-chromium,Eloston/ungoogled-chromium