Don't reset counters on RESTART

When ngIRCd restarts, all the connection counters are preserved now,
as well as the command counters for example.

It's unclear if resetting or not resetting is the "correct" behaviour,
but it's quite clear that the behaviour should be consistent for all the
counters ngIRCd uses ...

And initializing "WCounter", the global but temporary write counter,
is not necessarry at all: it is initialized (reset) before its use in
the command parser (see parse.c).