improve regular expression to parse Jerusalem timezone files

The previous regular expression failed to parse 32 timezone files
including Jersusalem. All timezone files are parsed(hopefully correctly)
by this regular expression.
fs-4762 paritally address.

scripts/perl/timezone-gen.pl

@@ -55,16 +55,13 @@ foreach my $name ( sort( keys(%name_to_file) ) ) {
     my $data = join( "", <$in> );
     close($in);
 
-    if ( $data !~ /^TZif/o ) {
+    my @strings = $data =~ (m/[ -~]{4,}/g);
+    if ( shift(@strings) !~ /^TZif/o ) {
         $debug && print "Skipped $file\n";
         next;
     }
 
-    my $tmp = $data;
-    $tmp =~ s/\n$//s;
-    $tmp =~ s/.*\n//sgmo;
-
-    $zones{$name} = $tmp;
+    $zones{$name} = pop(@strings);
 }
 
 open( my $out, ">$output" );