Make sure that intermediate certificates are available

As tests have shown it is not necessarily ensured that all the
intermediate certificates are in place. The added command will make
sure, that the DFN chain is imported in gpgsm.
8 jobs for 138-blog-post-s-mime-signing-of-git-commits in 4 minutes and 41 seconds (queued for 6 seconds)
Status Job ID Name Coverage
  Build
passed #112453
build:latest

00:02:01

passed #112456
build:production

00:03:28

passed #112455
build:production:review-apps

00:03:28

passed #112454
build:production:subpath

00:03:33

 
  Test
passed #112457
test:htmlproofer

00:00:56

passed #112458
test:htmlproofer:subpath

00:01:03

 
  Review
passed #112459
review-apps
review

00:00:06

passed #112460
review-apps manual
stop_review

00:00:02