ftpserver.pl: Fixed processing of IMAP authentication strings

        my $FTPARG;

        if($proto eq "imap") {

            # IMAP is different with its identifier first on the command line

            unless(($full =~ /^([^ ]+) ([^ ]+) (.*)/) ||

            if(($full =~ /^([^ ]+) ([^ ]+) (.*)/) ||

               ($full =~ /^([^ ]+) ([^ ]+)/)) {

                sendcontrol "$1 '$full': command not understood.\r\n";

                last;

            }

                $cmdid=$1; # set the global variable

                $FTPCMD=$2;

                $FTPARG=$3;

            }

            # IMAP long "commands" are base64 authentication data

            elsif($full =~ /^[A-Z0-9+\/]*={0,2}$/i) {

                # Command id has already been set

                $FTPCMD=$full;

                $FTPARG="";

            }

            else {

                sendcontrol "$1 '$full': command not understood.\r\n";

                last;

            }

        }

        elsif($full =~ /^([A-Z]{3,4})(\s(.*))?$/i) {

            $FTPCMD=$1;

            $FTPARG=$3;