The log_level in Swift is fixed to INFO. The patch make it changeable
according to the value of "openstack_logging_debug".
When "openstack_logging_debug" is "False", the log_level is set to
"INFO". It is default value. Otherwise, the log_level is set to
"DEBUG".
Closes-Bug: #1777982
Change-Id: I62f430abd8f332cc2ece56a6733776fa03b10f77
Signed-off-by: tone.zhang <tone.zhang@arm.com>