allow every client to ask for random seed.

assume this scenaio:
````
[scenario]
## human sides 1,2
  [event]
    name = prestart
    [message]
      speaker = narrator
      message = "Hello"
    [/message]
    {GENERIC_UNIT .....}
  [/event]
[/scenario]
```
previously, in this scenario client 2 would have to wait for side 1 to click away the [message] because of the random seed required by {GENERIC_UNIT ..} because only client 1 was allowed to ask the server for a random seed (Note that waiting during prestart event means black screen), this patch is intended to fix such situations.