remove videoOverlay back button

remove the button as it is not very useful now and will
be useless with the homepage removal.

Change-Id: I568b09e25819dbaf551f5a033d624407853b1f03
Reviewed-by: Anthony Léonard <anthony.leonard@savoirfairelinux.com>
diff --git a/callwidget.cpp b/callwidget.cpp
index f96d123..0043798 100644
--- a/callwidget.cpp
+++ b/callwidget.cpp
@@ -181,8 +181,7 @@
                 ui->currentAccountWidget, &CurrentAccountWidget::setPhoto);
 
         connect(ui->videoWidget, &VideoView::videoSettingsClicked, this, &CallWidget::settingsButtonClicked);
-        connect(ui->videoWidget, &VideoView::videoBackClicked, [=]{setActualCall(nullptr);
-                                                                    backToWelcomePage();});
+
         // setup searchingfor mini spinner
         miniSpinner_ = new QMovie(":/images/waiting.gif");
         ui->spinnerLabel->setMovie(miniSpinner_);