MB-9815: refresh certificate when user enters the tab

Change-Id: I24212da591e79391561a84251310de641c1f23e6
Reviewed-on: http://review.couchbase.org/31774
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>