Mark credits label as link-unaware

This significantly speeds up opening the credits screen.

src/gui/dialogs/end_credits.cpp

@@ -125,6 +125,7 @@ void end_credits::pre_show(window& window)
 	text_widget_ = find_widget<scroll_label>(&window, "text", false, true);
 
 	text_widget_->set_use_markup(true);
+	text_widget_->set_link_aware(false);
 	text_widget_->set_label((focus_ss.str().empty() ? ss : focus_ss).str());
 
 	// HACK: always hide the scrollbar, even if it's needed.

src/gui/widgets/scroll_label.cpp

@@ -103,6 +103,13 @@ void scroll_label::set_text_alpha(unsigned short alpha)
 	}
 }
 
+void scroll_label::set_link_aware(bool l)
+{
+	if(label* widget = get_internal_label()) {
+		widget->set_link_aware(l);
+	}
+}
+
 void scroll_label::set_self_active(const bool active)
 {
 	state_ = active ? ENABLED : DISABLED;

src/gui/widgets/scroll_label.hpp

@@ -71,6 +71,8 @@ class scroll_label : public scrollbar_container
 
 	void set_text_alpha(unsigned short alpha);
 
+	void set_link_aware(bool l);
+
 private:
 	/**
 	 * Possible states of the widget.