BUG/MEDIUM: sink: bad init sequence on tcp sink from a ring.

BUG/MEDIUM: sink: bad init sequence on tcp sink from a ring.

The init of tcp sink, particularly for SSL, was done
too early in the code, during parsing, and this can cause
a crash specially if nbthread was not configured.

This was detected by William using ASAN on a new regtest
on log forward.

This patch adds the 'struct proxy' created for a sink
to a list and this list is now submitted to the same init
code than the main proxies list or the log_forward's proxies
list. Doing this, we are assured to use the right init sequence.
It also removes the ini code for ssl from post section parsing.

This patch should be backported as far as v2.2

Note: this fix uses 'goto' labels created by commit
'BUG/MAJOR: log-forward: Fix log-forward proxies not fully initialized'
but this code didn't exist before v2.3 so this patch needs to be
adapted for v2.2.