MB-5307: avoid useless logs spamming by xdcr
MB-5307: avoid useless logs spamming by xdcr

Without this fix its logging "starting vb replication manager" each 5
seconds.

And it can be seen that for each defined replication it will log
message from inside of loop in manage_vbucket_replications. So we just
get rid of this log message.

Change-Id: Ib7527c16df958684001ddf66642dfdb73158ef90
Reviewed-on: http://review.couchbase.org/18001
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

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