Update Subscription.php

Author: Rotzbua

src/Subscription.php

@@ -28,7 +28,11 @@ public function __construct(
         private ?string $authToken = null,
         ContentEncoding|string|null $contentEncoding = null,
     ) {
-        if ($publicKey || $authToken || $contentEncoding) {
+        if (
+            (null !== $publicKey && '' !== $publicKey)
+            || (null !== $authToken && '' !== $authToken)
+            || null !== $contentEncoding
+        ) {
             if (is_string($contentEncoding)) {
                 try {
                     if (empty($contentEncoding)) {