glance: stop using deprecated notifier_strategy

Change-Id: Ic796f0ad57db45bf053312ad10815461528030b3
Remove unneeded guest conf values

Reasons:
 - guest service doesn't depend on "sql_connection" value any more;
 - "exchange_control" already set in trove-guestagent.conf.sample to "trove";

Change-Id: Ifbdb21ac4639d86cf7775634f5b31cfb9739b49f
Closes-Bug: #1256046
Merge "glance: stop using deprecated notifier_strategy"
Merge "Remove unneeded guest conf values"