Merge branch 'issues/143'

* issues/143:
  mkarchiso: Do not run _build_iso_base once
7 jobs for master in 31 minutes and 38 seconds (queued for 6 seconds)
Status Name Job ID Coverage
  Check
passed check #30255

00:00:13

 
  Build
passed build_long: [baseline iso] #30258
fast-single-thread

00:17:17

passed build_long: [baseline netboot] #30259
fast-single-thread

00:16:19

passed build_long: [releng iso] #30260
fast-single-thread

00:30:39

passed build_long: [releng netboot] #30261
fast-single-thread

00:31:22

passed build_short: [baseline bootstrap] #30256

00:12:57

passed build_short: [releng bootstrap] #30257

00:13:18