bin/rebuildPad.js: Don't overwrite DB settings
bin/rebuildPad.js: Don't overwrite DB settings

There's no need, and setting `json` to true breaks databases that do
their own serialization of ECMAScript objects.

ether/etherpad-lite,storytouch/etherpad-lite,ether/etherpad-lite,storytouch/etherpad-lite,ether/etherpad-lite,storytouch/etherpad-lite