fix: null safety handler when empty is passed to the masking method

Author: ibnsultan

src/Exception/Handler/PrettyPageHandler.php

@@ -832,7 +832,7 @@ public function hideSuperglobalKey($superGlobalName, $key)
      */
     private function masked(array $superGlobal, $superGlobalName)
     {
-        $blacklisted = $this->blacklist[$superGlobalName];
+        $blacklisted = $this->blacklist[$superGlobalName ?? ''] ?? [];
 
         $values = $superGlobal;