Update method signatures to use nullable types

Author: peterjaap

src/Api/ConfigurationInterface.php

@@ -8,10 +8,10 @@ interface ConfigurationInterface
                  CONFIG_RUMVISION_TRACKING_ID   = 'elgentos_rumvision/general/tracking_id',
                  CONFIG_RUMVISION_HOST_NAME     = 'elgentos_rumvision/general/hostname';
 
-    public function isEnabled(int $storeId = null): bool;
+    public function isEnabled(?int $storeId = null): bool;
 
-    public function getTrackingId(int $storeId = null) :string;
+    public function getTrackingId(?int $storeId = null) :string;
 
-    public function getHostName(int $storeId = null) :string;
+    public function getHostName(?int $storeId = null) :string;
 
-}
+}