Don't free memory that was never allocated. This fixes a core dump in

the case where both the config file and the default MTA don't exist.

PR:		29521
Submitted by:	marius@alchemy.franken.de

usr.sbin/mailwrapper/mailwrapper.c

@@ -130,7 +130,6 @@ main(argc, argv, envp)
 		closelog();
 		execve(_PATH_DEFAULTMTA, al.argv, envp);
 		freearg(&al, 0);
-		free(line);
 		err(1, "execing %s", _PATH_DEFAULTMTA);
 		/*NOTREACHED*/
 	}