PackageKitUpdater: Do not emit error when user cancels an update

A succesful cancelation is notified by the backend via the error
code `PackageKit::Transaction::ErrorTransactionCancelled`.

Do not emit an error message in this case, as it is the expected
outcome.

The same condition is used in PKTransaction.cpp:299

BEFORE:
![Screenshot_20220118_210009](/uploads/da7aeedcf88f67c3541fb3b61178951e/Screenshot_20220118_210009.png)

libdiscover/backends/PackageKitBackend/PKTransaction.cpp

@@ -296,8 +296,10 @@ void PKTransaction::eulaRequired(const QString &eulaID, const QString &packageID
 
 void PKTransaction::errorFound(PackageKit::Transaction::Error err, const QString &error)
 {
-    if (err == PackageKit::Transaction::ErrorNoLicenseAgreement || err == PackageKit::Transaction::ErrorTransactionCancelled)
+    if (err == PackageKit::Transaction::ErrorNoLicenseAgreement || err == PackageKit::Transaction::ErrorTransactionCancelled
+        || err == PackageKit::Transaction::ErrorNotAuthorized) {
         return;
+    }
     qWarning() << "PackageKit error:" << err << PackageKitMessages::errorMessage(err) << error;
     Q_EMIT passiveMessage(PackageKitMessages::errorMessage(err));
 }

libdiscover/backends/PackageKitBackend/PackageKitUpdater.cpp

@@ -553,8 +553,10 @@ void PackageKitUpdater::cancel()
 
 void PackageKitUpdater::errorFound(PackageKit::Transaction::Error err, const QString &error)
 {
-    if (err == PackageKit::Transaction::ErrorNoLicenseAgreement)
+    if (err == PackageKit::Transaction::ErrorNoLicenseAgreement || err == PackageKit::Transaction::ErrorTransactionCancelled
+        || err == PackageKit::Transaction::ErrorNotAuthorized) {
         return;
+    }
     QString finalMessage = xi18nc("@info", "%1:<nl/><nl/>%2", PackageKitMessages::errorMessage(err), error);
     Q_EMIT passiveMessage(finalMessage);
     qWarning() << "Error happened" << err << error;