[devtools] fix a couple issues with xvfb-run xvfb-run didn't quite clean up correctly after itself, because: - dash doesn't run EXIT traps on signals - if we don't run the command in the background, a TERM handler doesn't run until the command exits

#! /bin/sh -e
#

if [ "$1" = remove -o "$1" = upgrade ]; then
  if which install-docs >/dev/null 2>&1; then
    install-docs -r cubicweb-doc
  fi
fi

#DEBHELPER#

exit 0