Catch the exception in LDAP auth (Bug #1009262)

Scrub the password from the error output and turn it into stars

Change-Id: Ie3cbf485ea2173e74364ae8505615a74b8f1c248
Signed-off-by: Son Nguyen <son.nguyen@catalyst.net.nz>
Merge "Catch the exception in LDAP auth (Bug #1009262)"