CI: Handle missing package index

1 job for master in 14 seconds (queued for 2 seconds)
Name Stage Failure
deploy-plugins Deploy
  File "/builds/gajim/gajim-plugins/.ci/", line 49, in func_wrapper
func(ftp, *args)
File "/builds/gajim/gajim-plugins/.ci/", line 141, in deploy
upload_file(ftp, image_path)
File "/builds/gajim/gajim-plugins/.ci/", line 112, in upload_file
with open(filepath, 'rb') as f:
FileNotFoundError: [Errno 2] No such file or directory: '/builds/gajim/gajim-plugins/openpgp/openpgp.png'
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1