MB-10703: Check replication status before pause/resume request

Change-Id: If89cd99f9952ddc19b0c2ea7110c7235ed1f0279
Reviewed-on: http://review.couchbase.org/35982
Reviewed-by: Bin Cui <bin.cui@gmail.com>
Tested-by: Bin Cui <bin.cui@gmail.com>