[config] don't save config on set

Fixes beat.editor#277
4 jobs for config-set-dont-save in 4 minutes and 5 seconds (queued for 1 second)
Status Name Job ID Coverage
  Build
passed build_linux_36 #204710
docker-build

00:03:04

58.0%
passed build_linux_37 #204711
docker-build

00:02:57

58.0%
passed build_macosx_36 #204708
macosx

00:04:05

58.0%
passed build_macosx_37 #204709
macosx

00:03:54

58.0%