Initialize progress right away with QtWebKit 5.212 (ariya#15342)

Apparently loading progress used to move beyond 0 right after the
frame start loading an URI, even before there is network traffic.

This behavior compatibility prevents the regression on the test
module/webpage/loading.js.

Author: ariya

Diff for: src/webpage.cpp

@@ -951,6 +951,9 @@ void WebPage::openUrl(const QString& address, const QVariant& op, const QVariant
 
         request.setUrl(url);
         m_mainFrame->load(request, networkOp, body);
+
+        // Emulate the behavior of old QtWebKit
+        m_loadingProgress = 1;
     }
 }
 

Diff for: test/module/webpage/loading.js

@@ -18,6 +18,4 @@ async_test(function () {
 
     assert_is_true(page.loading);
     assert_greater_than(page.loadingProgress, 0);
-}, "page loading progress",
-    { skip: true }   // FIXME
-);
+}, "page loading progress");