Fix build with newer compilers

Index: source/libs/paragui/src/widgets/pgwidget.cpp
--- source/libs/paragui/src/widgets/pgwidget.cpp.orig
+++ source/libs/paragui/src/widgets/pgwidget.cpp
@@ -1792,7 +1792,7 @@ PG_Widget* PG_Widget::GetParent() {
 	return _mid->widgetParent;
 }
 
-int PG_Widget::GetID() {
+unsigned int PG_Widget::GetID() {
 	return _mid->id;
 }
 
