Init with many features can fail with psycopg2.OperationalError

[wonder-sk]

It has been seen in testing that when using a remote PostgreSQL server and a table with many rows, the init (from gpkg) can consistently fail.

Probably related to #45

Traceback (most recent call last):
  File "dbsync_daemon.py", line 216, in <module>
  File "dbsync_daemon.py", line 175, in main
  File "dbsync.py", line 1450, in dbsync_init
  File "dbsync.py", line 1319, in init
  File "dbsync.py", line 586, in _set_db_project_comment
psycopg2.OperationalError: server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.