MB-4893 Don't hang forever in ns_memcached:init.
MB-4893 Don't hang forever in ns_memcached:init.

If for some reason ns_memcached is not able to connect to memcached it
will try doing this forever. And since this happens in init callback,
it will block parent supervisor. Thus it makes it impossible to
terminate the parent in a graceful way.

Change-Id: If6b7536e70852ddd226410320e7d1957d3dc9dcc
Reviewed-on: http://review.couchbase.org/14496
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

t3rm1n4l/ns_server,nimishzynga/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,membase/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,daverigby/ns_server,mschoch/ns_server,mschoch/ns_server,pavel-blagodov/ns_server,mschoch/ns_server,ceejatec/ns_server,daverigby/ns_server,ceejatec/ns_server,mschoch/ns_server,vzasade/ns_server,nimishzynga/ns_server,ceejatec/ns_server,pavel-blagodov/ns_server,membase/ns_server,ceejatec/ns_server,vzasade/ns_server,pavel-blagodov/ns_server,vzasade/ns_server,membase/ns_server,t3rm1n4l/ns_server,membase/ns_server,pavel-blagodov/ns_server,daverigby/ns_server,nimishzynga/ns_server,vzasade/ns_server,daverigby/ns_server,ceejatec/ns_server,membase/ns_server,mschoch/ns_server,nimishzynga/ns_server,daverigby/ns_server