Highlight the URL in the add stream dialog when it's opened

src/ui/addstreamdialog.cpp

@@ -96,3 +96,7 @@ void AddStreamDialog::TextChanged(const QString &text) {
   ui_->button_box->button(QDialogButtonBox::Ok)->setEnabled(valid);
 }
 
+void AddStreamDialog::showEvent(QShowEvent *) {
+  ui_->url->setFocus();
+  ui_->url->selectAll();
+}

src/ui/addstreamdialog.h

@@ -40,6 +40,9 @@ class AddStreamDialog : public QDialog {
 
   void accept();
 
+ protected:
+  void showEvent(QShowEvent *);
+
  private slots:
   void TextChanged(const QString& text);