Add support for empty session write

- Ignored empty data left session intact, leading to unexpected behaviors

src/Core/Session/Handler/Cache.php

@@ -87,7 +87,7 @@ class Cache implements SessionHandlerInterface
 		}
 
 		if (!$session_data) {
-			return true;
+			return $this->destroy($session_id);
 		}
 
 		return $this->cache->set('session:' . $session_id, $session_data, Session::$expire);

src/Core/Session/Handler/Database.php

@@ -94,7 +94,7 @@ class Database implements SessionHandlerInterface
 		}
 
 		if (!$session_data) {
-			return true;
+			return $this->destroy($session_id);
 		}
 
 		$expire         = time() + Session::$expire;