remove the cancel button in case where it would be ignored

src/dialogxml/dialogs/pictchoice.cpp

@@ -157,3 +157,7 @@ ePicType cPictChoice::getPicChosenType() const {
 size_t cPictChoice::getSelected() const {
 	return cur;
 }
+
+void cPictChoice::disableCancel() {
+	dlg["cancel"].hide();
+}

src/dialogxml/dialogs/pictchoice.hpp

@@ -75,6 +75,8 @@ public:
 	/// Get the index of the selected icon in the original list.
 	/// @return The index
 	size_t getSelected() const;
+	/// Disallow the player from cancelling without making a choice
+	void disableCancel();
 };
 
 #endif