Revert "Keeping open the DbServer client socket [skip hazardlib][demos]"
Revert "Keeping open the DbServer client socket [skip hazardlib][demos]"

This reverts commit 7d32833c014f64fe10c8ddb6d411814b3e228df4 [formerly dfcac8f6a6aaed93d7d4769c3a5a0b77c6d04e6e] [formerly a2ea42ae426b830993981dc081ef5f19dcf19e34 [formerly a483d582f6b34e68f89c9e73caaa6377f77ae5b2]].


Former-commit-id: a8cf8a7ca492418cf4f9ba426257ab26564b6cd0 [formerly 51caacf2bed752cb48354ab639ffae63335515b2]
Former-commit-id: b4e7fbf2172d27f4ed28a8d4b7c7643960d75ddf
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine