MB-8088: prevent max_restart_intensity_reached during node rename

In MB-8088 we can see that supervisor2 {permanent,4} is not very
effective it seems. When two such processes crash it may go into
max_restart_intensity_reached state.

As a somewhat kludgy fix we'll just delay crashes of those 2 guys that
depend on access to babysitter during node renaming.

Change-Id: Ie69fa4c04bde369b08f696f4bdb88cc2be12ace4
Reviewed-on: http://review.couchbase.org/25666
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>