Use unversioned Perl.

--- help2man-1.49.3/help2man.PL.orig
+++ help2man-1.49.3/help2man.PL
@@ -47,7 +47,7 @@
     unless $opts{quiet};
 
 # Add startup header.
-print OUT "$Config{startperl} -w\n";
+print OUT "#!/usr/bin/perl -w\n";
 
 # For systems without the crash-bang hack also add:
 print OUT <<"!GROK!THIS!" if $Config{sharpbang} !~ /^#!/;