Fix spectator unit list key press handling

By setting maxHistroyDelay really high, the unit list shouldn't be messed with via key press very often.

addons/spectator/UI/interface.hpp

@@ -190,6 +190,7 @@ class GVAR(interface) {
                         1
                     };
                     multiselectEnabled = 0;
+                    maxHistoryDelay = 10e10;
                     onTreeDblClick = QUOTE([ARR_2('onTreeDblClick',_this)] call FUNC(handleInterface));
                 };
                 class unitFrame: RscFrame {