MB-9954: Check if port is integer
MB-9954: Check if port is integer

Otherwise, give better error message

Change-Id: I3b4d82584882a05153d8d4224533acff0c99c58a
Reviewed-on: http://review.couchbase.org/38414
Reviewed-by: Bin Cui <ed18693fff32c00e22495f4877a3b901bed09041@gmail.com>
Tested-by: Bin Cui <ed18693fff32c00e22495f4877a3b901bed09041@gmail.com>

couchbase/couchbase-cli,couchbase/couchbase-cli