[feature/request-class] Add is_secure method to request for HTTPS

PHPBB3-9716

phpBB/includes/request/request.php

@@ -326,6 +326,16 @@ class phpbb_request implements phpbb_request_interface
 		return $this->header('X-Requested-With') == 'XMLHttpRequest';
 	}
 
+	/**
+	* Checks if the current request is happening over HTTPS.
+	*
+	* @return	bool			True if the request is secure.
+	*/
+	public function is_secure()
+	{
+		return $this->server('HTTPS') == 'on';
+	}
+
 	/**
 	* Returns all variable names for a given super global
 	*