ctdb-protocol: Fix marshalling for GET_DB_SEQNUM control

ctdb-protocol: Fix marshalling for GET_DB_SEQNUM control

In the control request, database id which is a 32-bit integer is sent
on wire as a 64-bit integer rather than a 32-bit integer.  If we
convert the database id to 64-bit integer before sending, the order of
32-bits with database id will vary depending on the endian-ness.

Instead send the database id as first 32-bits and zeros as next 32-bits.

Signed-off-by: Amitay Isaacs <amitay@gmail.com>
Reviewed-by: Martin Schwenke <martin@meltin.net>