deb: make CI happy when running on trusty
deb: make CI happy when running on trusty

Former-commit-id: 6141b476750bc510758f614740b46becabdf3335 [formerly 33208b0d54611843ef7bb035b625f7d8c0d241e2]
Former-commit-id: 73c59912f6265962f465754c72358733b77e458c
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine