removing backarc hardcoding
removing backarc hardcoding


Former-commit-id: bb1b2c61e7085a29a81a2f272cfa8089a9762f0f [formerly bb1b2c61e7085a29a81a2f272cfa8089a9762f0f [formerly be377e4d75b3d1615a50e536202584f1633b23ca]]
Former-commit-id: de0ac1f1ec8d5a25b7e3c90f94f7a2445c827c8c
Former-commit-id: 51d3e92350902e802231e016ed49dd8fc8d4bd95
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine