Fix domain database initialization

To fix bug 1089916, calls to db_api.configure_db() were changed to
setup_db_env(). However, the gateway domain initialization didn't get
the memo. This patch makes sure setup_db_env() is called in all the
relevant places.

Fixes bug 1131705.

Change-Id: Ieec141192b8a5a045dadba6d70abaa25748b85b2
Merge "Fix domain database initialization"