Improved an error message [skip CI]
Improved an error message [skip CI]


Former-commit-id: f18e1e29ad7572ce0c7a4131cd35df9fa5798395 [formerly f18e1e29ad7572ce0c7a4131cd35df9fa5798395 [formerly 172cdd6b126ee0849bc98298ac27b08d431483cc]]
Former-commit-id: 2fe15e2eb04dce0c28793a4333b43c3f01fe163b
Former-commit-id: f17ccd6ec542b32bc5dff2e391499644fc27382e
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine