cron: fix cron installation

cron.pl

@@ -14,12 +14,13 @@ if (-d "/opt/fi-printers") {
 else
 {
     my $output = `git clone https://gitlab.fi.muni.cz/unix/fi-printers.git /opt/fi-printers`;
+    chdir "/opt/fi-printers";
 }
 
 # copy cron.pl into weekly cron
 copy("/opt/fi-printers/cron.pl", "/etc/cron.weekly/fi_printers_cron");
 
-my @files = glob( '/etc/cups/ppd/*fi.muni.ppd' );
+my @files = glob('/etc/cups/ppd/*fi.muni.ppd');
 
 for my $item (@files) {
     print "current $item\n";