CHintBox: ensure remove timeout bar from screen if hintbox object is closed

Timeout bar is not embedded like other cc items in  this form, therefor is
is better to kill this object explicit from screen otherwise it is possible
we hab artefacts after closing of hintbox window.

src/gui/widget/hintbox.cpp

@@ -167,6 +167,7 @@ void CHintBox::init(const std::string& Text, const int& Width, const std::string
 CHintBox::~CHintBox()
 {
 	if(timeout_pb){
+		timeout_pb->kill(); //ensure cleanup from screen
 		delete timeout_pb; timeout_pb = NULL;
 	}
 	if(timeout_pb_timer){