gitweb fix validating pg (page) parameter

Currently it is possible to give any string ending with a number as
page.  -1 for example is quite bad (error log shows probably 100
warnings).

Signed-off-by: Junio C Hamano <junkio@cox.net>

gitweb/gitweb.perl

@@ -256,7 +256,7 @@ if (defined $hash_parent_base) {
 
 our $page = $cgi->param('pg');
 if (defined $page) {
-	if ($page =~ m/[^0-9]$/) {
+	if ($page =~ m/[^0-9]/) {
 		die_error(undef, "Invalid page parameter");
 	}
 }