fix Sendmail handler

mailman/mailman-sendmail.m4

@@ -10,7 +10,7 @@ MAILER_DEFINITIONS
 ##  mailman handler assumes this behavior to avoid having to know too
 ##  much about address parsing and other RFC-2822 mail details.
 
-Mmailman,	P=@l_prefix@/libexec/mailman/mail/mailman.pl, F=rDFMhlqSu, U=@l_nusr@:@l_ngrp@,
+Mmailman,	P=@l_prefix@/libexec/mailman/mail/mailman-sendmail, F=rDFMhlqSu, U=@l_nusr@:@l_ngrp@,
 		S=EnvFromL, R=EnvToL/HdrToL,
-		A=mailman $h $u
+		A=mailman-sendmail $h $u