Don't display groups if you are not logged in

ldap/group.go

@@ -17,6 +17,10 @@ type Group struct {
 
 // InGroup checks if user is part of group
 func (l Ldap) InGroup(user string, group string) bool {
+	if user == "" {
+		return false
+	}
+
 	conn, err := l.connect()
 	if err != nil {
 		return false