Stable connection to server for longer times during work with session

[FrankUrbach]

In Julia versions > 1.7.2 the every 4 seconds needed ping to the database server isn't stable after a few minutes of running a session. Above the mentioned Julia version something was changed in the Thread mechanism where the ping lives in the lifespan of the session. As it seems to be the grpc client isn't thread safe in conjunction with the thread mechanism of Julia above 1.7.2