Use the ID within WebEngineView to make it work with Qt 5.7

I have no idea why, I think it might be some timing issues while
initializing the webengine, but when using runJavaScript() in
the WebEngineView without referencing it with the id of that
QML object it just throws the error that it doesn't know what
runJavaScript() is. When we use the ID then it just works
for some reason.

qml/Content.qml

@@ -48,18 +48,18 @@ Item {
 
         function setPost() {
             if(post) {
-                runJavaScript("setArticle(" + post.jsonString + ")")
+                webView.runJavaScript("setArticle(" + post.jsonString + ")")
             } else {
-                runJavaScript("setArticle('logout')")
+                webView.runJavaScript("setArticle('logout')")
             }
         }
 
         function setDefaults() {
             // font name needs to be enclosed in single quotes
             // and this is needed for El Capitain because ".SF NS Text" won't work
             var defFont = ', system, -apple-system, ".SFNSDisplay-Regular", "Helvetica Neue", "Lucida Grande"';
-            runJavaScript("document.body.style.fontFamily = \"'" + fontLabel.font.family + "'" + defFont + "\";");
-            runJavaScript("document.body.style.fontSize = '" + content.textFontSize + "pt';");
+            webView.runJavaScript("document.body.style.fontFamily = \"'" + fontLabel.font.family + "'" + defFont + "\";");
+            webView.runJavaScript("document.body.style.fontSize = '" + content.textFontSize + "pt';");
         }