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

This reverts commit a483d582f6b34e68f89c9e73caaa6377f77ae5b2.

gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine