cron_advertise.pl is strongly biased when choosing ads

[Stefan Steinheimer]

e.g. if only the first and last file in @adcreditfiles have credit, and there are n files, it will choose $adcreditfiles[0] only when $r == 0, and $adcreditfiles[n-1] in all other cases. Proposed solution: delete credit files when credit runs out.

[14mRh4X0r]

I replaced

my @adcreditfiles = <${addir}/cred-*>;

with

my @adcreditfiles = `grep -lv '^0\$' ${addir}/cred-*`;
chomp @adcreditfiles;

so cred-[timestamp] files with a value of 0 get filtered out.

I did it this way instead of removing them, since exec_advertise.pl expects that file to exist if the timestamp exists in account-[someuser]. Removing the timestamp from that file would mean removing the whole ad when all credits are spent, which is not what we want.

[Riot]

Issue #155 was marked as a duplicate of this issue.