Change-Character-Attack protection

If chooser changes character too quickly, server just breaks down with
some error (but it not restarts, just does not let anyone in)

This protections kicks players what changes characters too quickly and
too much)

assets/src/ba_data/python/ba/_lobby.py

@@ -35,6 +35,10 @@ if TYPE_CHECKING:
     import ba
 
 
+MAX_QUICK_CHANGE_COUNT = 30
+QUICK_CHANGE_INTERVAL = 0.05
+
+
 # Hmm should we move this to actors?..
 class JoinInfo:
     """Display useful info for joiners."""
@@ -169,6 +173,7 @@ class Chooser:
         self._profilenames: List[str] = []
         self._ready: bool = False
         self.character_names: List[str] = []
+        self.last_change: Sequence[Union[float, count]] = (0, 0)
 
         # Hmm does this need to be public?
         self.profiles: Dict[str, Dict[str, Any]] = {}
@@ -663,6 +668,13 @@ class Chooser:
     def handlemessage(self, msg: Any) -> Any:
         """Standard generic message handler."""
         if isinstance(msg, ChangeMessage):
+            now = ba.time()
+            count = self.last_change[1] + 1
+            if now - self.last_change[0] < QUICK_CHANGE_INTERVAL and count > MAX_QUICK_CHANGE_COUNT:
+                # Hmm maybe we should notify client?
+                _ba.disconnect_client(self._player.get_input_device().client_id)
+            self.last_change = (now, count)
+0
 
             # If we've been removed from the lobby, ignore this stuff.
             if self._dead: