Fix recent regression in 3c6becd5 where login or hg login to variable sized regions failed with outdated simulator message.

I forgot that a null 'their version' would not be passed over the wire and ends up as an empty string instead (like older simulators).
So instead pass through the correct simulator protcol version instead (SIMULATOR/0.3) when querying from login or hg login.
Also removes a debug console write for agent limit accidentally left in for the same commit.
Relates to mantis 7276