Mark sql_connection with secret flag

sql_connection contains the password in some setups and marking as
secret prevents accidental logging

fixes bug 1160680

Change-Id: I3704237d0923bb30138b5ece7e5c7bbda0a78b9b
(cherry picked from commit 9f8ee9d)

cinder/flags.py

@@ -81,7 +81,8 @@ def _get_my_ip():
     cfg.StrOpt('sql_connection',
                default='sqlite:///$state_path/$sqlite_db',
                help='The SQLAlchemy connection string used to connect to the '
-                    'database'),
+                    'database',
+               secret=True),
     cfg.IntOpt('sql_connection_debug',
                default=0,
                help='Verbosity of SQL debugging information. 0=None, '