MB-10857: Temporary auto-enable datatype for UPR

Some of the UPR consumers don't send the HELLO command to
enable support for the datatype bit, causing the the connection
to be shut down when an item with a non-null datatype is set.

Change-Id: Icb1e27033f2a375a85f2279876d5056b059968f2
Reviewed-on: http://review.couchbase.org/35893
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>