Abort client-connect handler loop after first handler sets 'disable'.

Abort client-connect handler loop after first handler sets 'disable'.

The old code would run all (succeeding) handlers, then discover "one of
them set the 'disable' flag for this client", and then unroll all the
handlers.

Moving the 'disable' check into the loop makes it stop after the first
handler that fails or (succeeds and sets 'disable').  This is a bit
more logical in the log files, and has less potential side effects
due to running "later" client-connect handlers when we already know
they will have to be unrolled.

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20200727183436.6625-2-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20612.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>