HPCC-12399 Address cleaner socket updates

Added writetms routine for address cleaner plugin (in LN repo)

This PR goes together with an LN repo PR #705

https://github.com/hpcc-systems/LN/pull/705

Signed-off-by: Mark Kelly <mark.kelly@lexisnexis.com>
size32_t is an unsigned value, so this condition will only be true if (amt == 0)