Confirm to trust certificate when there is error

For #26

src/browser/index.jsx

@@ -221,6 +221,10 @@ var MattermostView = React.createClass({
 
     webview.addEventListener('did-fail-load', function(e) {
       console.log(thisObj.props.name, 'webview did-fail-load', e);
+      if (e.errorCode === -3) { // An operation was aborted (due to user action).
+        return;
+      }
+
       // should use permanent way to indicate
       var did_fail_load_notification = new Notification(`Failed to load "${thisObj.props.name}"`, {
         body: `ErrorCode: ${e.errorCode}`,