set focus on message input when showing page

When switching to messaging page the focus is automatically set to
the text input.

Change-Id: I7b01f0e25186e87b260bd82e273f4ea52f31c51d
Reviewed-by: Anthony Léonard <anthony.leonard@savoirfairelinux.com>

callwidget.cpp

@@ -804,6 +804,8 @@ CallWidget::showIMOutOfCall(const QModelIndex& nodeIdx)
     ui->sendContactRequestPageButton->setVisible(shouldDisplayInviteButton(*cmVector[0]));
 
     ui->stackedWidget->setCurrentWidget(ui->messagingPage);
+    ui->imMessageEdit->clear();
+    ui->imMessageEdit->setFocus();
     disconnect(imClickedConnection_);
     imClickedConnection_ = connect(ui->listMessageView, &QListView::clicked, [this](const QModelIndex& index) {
         auto urlList = index.data(static_cast<int>(Media::TextRecording::Role::LinkList)).value<QList<QUrl>>();