Fix language tag logic

php/servers/servers-rooms.php

@@ -180,7 +180,7 @@
 		public function get_language_flag(): string {
 			global $languages;
 
-			if (isset($this->language_flag)) {
+			if (!empty($this->language_flag)) {
 				return $this->language_flag;
 			}
 
@@ -433,7 +433,7 @@
 				return false;
 			}
 
-			if (isset($this->language_flag)) {
+			if (!empty($this->language_flag)) {
 				log_warning("Language is already $this->language_flag, parsing $tag");
 				return true;
 			}
@@ -452,6 +452,7 @@
 				}, $chars);
 				$this->language_flag = implode($flag_chars);
 			} else {
+				log_warning("Invalid language code: $lang");
 				return false; // Invalid language flag
 			}