Fix %preun to not erroneously wipe httpd conf files

4 jobs from el7 in 10 minutes and 8 seconds (queued for 10 seconds)
Status Job ID Name Coverage
  Build
passed #11145
build_bionic

00:03:10

passed #11144
build_buster

00:03:23

passed #11143
build_stretch

00:03:20

 
  Sign
failed #11146
sign

00:00:14

 
Name Stage Failure
failed
sign Sign
$ ci-sign-pkg
========================================================================
=
= Configure and check
=
declare -x CI_COMMIT_REF_NAME="el7"
declare -- RESULT_DIR="result"
ci-sign-pkg: use GPG_PRIVATE_KEY (runner) or GPG_USER_ID (workstation)
ERROR: Job failed: exit code 1