Corrected return value for Session/RedisHandler::read to string, per PHP specs.

Author: lonnieezell

system/Session/Handlers/RedisHandler.php

@@ -178,22 +178,22 @@ public function open($save_path, $name): bool
 	 *
 	 * @return string|false	Serialized session data
 	 */
-	public function read($sessionID)
+	public function read($sessionID): string
 	{
 		if (isset($this->redis) && $this->lockSession($sessionID))
 		{
 			// Needed by write() to detect session_regenerate_id() calls
 			$this->sessionID = $sessionID;
 
-			$session_data = $this->redis->get($this->keyPrefix . $sessionID);
+			$session_data                               = $this->redis->get($this->keyPrefix . $sessionID);
 			is_string($session_data) ? $this->keyExists = true : $session_data = '';
 
 			$this->fingerprint = md5($session_data);
 
 			return $session_data;
 		}
 
-		return false;
+		return '';
 	}
 
 	//--------------------------------------------------------------------