add 'network' permission

res/project.toml

@@ -1,3 +1,6 @@
 # default project
 name = "default"
 base_packs = ["base"]
+permissions = [
+    "network"
+]

res/scripts/classes.lua

@@ -182,6 +182,9 @@ local function clean(iterable, checkFun, ...)
 end
 
 network.__process_events = function()
+    if not network.is_available() then
+        return
+    end
     local CLIENT_CONNECTED = 1
     local CONNECTED_TO_SERVER = 2
     local DATAGRAM = 3