ftpserver.pl: Updated custom full text REPLY regex

SASL downgrade tests: 833, 835, 879, 881, 935 and 937 would fail as
they contained a minus sign in their authentication mechanism and this
would be missed by the custom reply parser.

tests/ftpserver.pl

@@ -2843,7 +2843,7 @@ sub customize {
     logmsg "FTPD: Getting commands from log/ftpserver.cmd\n";
 
     while(<CUSTOM>) {
-        if($_ =~ /REPLY \"([A-Z]+ [A-Za-z0-9+\/=\*]+)\" (.*)/) {
+        if($_ =~ /REPLY \"([A-Z]+ [A-Za-z0-9+-\/=\*]+)\" (.*)/) {
             $fulltextreply{$1}=eval "qq{$2}";
             logmsg "FTPD: set custom reply for $1\n";
         }