Silence perl complaint in ssl test

Perl's hex() function complains if its argument contains trailing white
space (or in fact anything other than hex digits), so remove the
offending text.

src/test/ssl/t/001_ssltests.pl

@@ -504,6 +504,7 @@ if ($? == 0)
 	if ($Config{ivsize} == 8)
 	{
 		$serialno =~ s/^serial=//;
+		$serialno =~ s/\s+//g;
 		$serialno = hex($serialno);
 	}
 	else