remove unused import
remove unused import


Former-commit-id: f8a79686bad27f2a464098f49ba707c1bd281a42 [formerly 3822e4f086443b0f3c3fc4078b2b530209e7898e] [formerly 3822e4f086443b0f3c3fc4078b2b530209e7898e [formerly 76ae74049c4c5aaf708de7c7dd4d241f335ac54e]]
Former-commit-id: 360d4e414df9caf53d914f4ea6c10918c506efec
Former-commit-id: 35a059b9fe999bc755877cb79e16f07cd1acee9d
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine