fix authentication using provider page and web page login flow

Signed-off-by: Matthieu Gallien <matthieu.gallien@nextcloud.com>

src/gui/owncloudsetupwizard.cpp

@@ -333,7 +333,9 @@ void OwncloudSetupWizard::slotConnectToOCUrl(const QString &url)
 {
     qCInfo(lcWizard) << "Connect to url: " << url;
     AbstractCredentials *creds = _ocWizard->getCredentials();
-    _ocWizard->account()->setCredentials(creds);
+    if (creds) {
+        _ocWizard->account()->setCredentials(creds);
+    }
 
     const auto fetchUserNameJob = new JsonApiJob(_ocWizard->account()->sharedFromThis(), QStringLiteral("/ocs/v1.php/cloud/user"));
     connect(fetchUserNameJob, &JsonApiJob::jsonReceived, this, [this, url](const QJsonDocument &json, int statusCode) {

src/gui/wizard/welcomepage.cpp

@@ -96,7 +96,7 @@ void WelcomePage::setupCreateAccountButton()
     connect(_ui->createAccountButton, &QPushButton::clicked, this, [this](bool /*checked*/) {
         _ocWizard->setRegistration(true);
         _nextPage = WizardCommon::Page_WebView;
-        _ocWizard->next();
+        _ocWizard->setAuthType(OCC::DetermineAuthTypeJob::WebViewFlow);
     });
 #else // WITH_WEBENGINE
     connect(_ui->createAccountButton, &QPushButton::clicked, this, [this](bool /*checked*/) {