gitweb: Git config keys are case insensitive, make config search too

"git config -z -l" that gitweb uses in git_parse_project_config() to
populate %config hash returns section and key names of config
variables in lowercase (they are case insensitive).  When checking
%config in git_get_project_config() we have to take it into account.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

gitweb/gitweb.perl

@@ -2510,6 +2510,13 @@ sub git_get_project_config {
 
 	# key sanity check
 	return unless ($key);
+	# only subsection, if exists, is case sensitive,
+	# and not lowercased by 'git config -z -l'
+	if (my ($hi, $mi, $lo) = ($key =~ /^([^.]*)\.(.*)\.([^.]*)$/)) {
+		$key = join(".", lc($hi), $mi, lc($lo));
+	} else {
+		$key = lc($key);
+	}
 	$key =~ s/^gitweb\.//;
 	return if ($key =~ m/\W/);