fix: getGlobalProcessId() -> incorrect return value

Related: #154

src/QUI/ERP/Accounting/Invoice/Invoice.php

@@ -157,6 +157,8 @@ public function __construct($id, Handler $Handler)
 
         if ($this->getAttribute('global_process_id')) {
             $this->globalProcessId = $this->getAttribute('global_process_id');
+        } else {
+            $this->globalProcessId = $this->getUUID();
         }
 
         // invoice payment data