Remove NULL frees handled by clear_channel above.

src/mod/channels.mod/channels.cc

@@ -712,8 +712,6 @@ void remove_channel(struct chanset_t *chan)
    if (chan->groups) {
      delete(chan->groups);
    }
-   delete chan->channel.floodtime;
-   delete chan->channel.floodnum;
    free(chan);
 }