Fix bug with CSM restrictions

init.lua

@@ -124,12 +124,14 @@ chat_channels.get_channel_users = function(c)
         if not connected_players[name] then
             local empty           = true
             local visible_players = minetest.get_player_names()
+            if visible_players then
                 for _, player in ipairs(visible_players) do
                     if player == name then
                         empty = false
                         break
                     end
                 end
+            end
             if empty then return {} end
         end
         return {name}