GUI: Update worker type if task already exist.

So it doesn't invalidly re-use the cached one.

src/qt/pivx/loadingdialog.h

@@ -25,6 +25,7 @@ class Worker : public QObject {
         runnable = nullptr;
     }
     virtual void clean() {};
+    void setType(int _type) { type = _type; }
 public Q_SLOTS:
     void process();
 Q_SIGNALS:

src/qt/pivx/pwidget.cpp

@@ -108,6 +108,8 @@ bool PWidget::execute(int type, std::unique_ptr<WalletModel::UnlockContext> pctx
             WalletWorker* _worker = static_cast<WalletWorker*>(task->worker.data());
             _worker->setContext(std::move(pctx));
         }
+        // Update type
+        task->worker->setType(type);
     }
     QThreadPool::globalInstance()->start(task.data());
     return true;