GUI2/Multimenu Button: store max shown count as an unsigned int

A negative count here makes no sense...

src/gui/widgets/multimenu_button.cpp

@@ -166,8 +166,8 @@ void multimenu_button::update_label()
 	if(selected.size() == values_.size()) {
 		set_label(_("multimenu^All Selected"));
 	} else {
-		if(selected.size() > static_cast<size_t>(max_shown_)) {
-			const int excess = selected.size() - max_shown_;
+		if(selected.size() > max_shown_) {
+			const unsigned excess = selected.size() - max_shown_;
 			selected.resize(max_shown_ + 1);
 			selected.back() = VNGETTEXT("multimenu^$excess other", "$excess others", excess, {{"excess", std::to_string(excess)}});
 		}

src/gui/widgets/multimenu_button.hpp

@@ -62,7 +62,7 @@ class multimenu_button : public styled_widget
 	 *
 	 * @param max      The maximum number of elements to show
 	 */
-	void set_max_shown(const int max)
+	void set_max_shown(const unsigned max)
 	{
 		max_shown_ = max;
 	}
@@ -72,7 +72,7 @@ class multimenu_button : public styled_widget
 	 *
 	 * @returns        The maximum number of elements to show
 	 */
-	int get_max_shown()
+	unsigned get_max_shown()
 	{
 		return max_shown_;
 	}
@@ -150,7 +150,7 @@ class multimenu_button : public styled_widget
 	/**
 	 * The maximum number of selected states to list in the label
 	 */
-	int max_shown_;
+	unsigned max_shown_;
 
 	std::vector<::config> values_;
 
@@ -208,7 +208,7 @@ struct builder_multimenu_button : public builder_styled_widget
 	widget* build() const;
 
 private:
-	int max_shown_;
+	unsigned max_shown_;
 	std::vector<::config> options_;
 };