SIGALRM cleanup in smtpserver under inetd

[Ken Pizzini <ken@ember.spry.com>]

On a machine running Zmailer 2.99.26 I kept finding abandoned
files from smtpserver in $POSTOFFICE/public .  I think that I've
finally isolated the problem: this machine runs smtpserver through
inetd, and the timedout() handler (which does file clean-up) for
SIGALRM is only enabled on the else branch of an "if (inetd)" test.
Thus if a session times out on an inetd-spawned smtpserver then
any temporary file created in $POSTOFFICE/public will be left there.

		--Ken Pizzini