Fixed SW QoS doc to use getClusterNodes (#578)

The QUIC tpu port number was incorrectly listed in
the docs. This change tells the user to get the
QUIC tpu port from the getClusterNodes RPC call.

content/guides/advanced/stake-weighted-qos.md

@@ -140,9 +140,8 @@ On the RPC you will have to use `--rpc-send-transaction-tpu-peer` to forward
 transactions to a specific leader. The exact usage would be
 `--rpc-send-transaction-tpu-peer HOST:PORT`. The Host is the ip address of the
 leader you have the `staked-nodes-overrides` enabled on and the Port is the QUIC
-TPU port of that host. The QUIC TPU port number is the lowest value of your
-`--dynamic-port-range` plus 9. For example, if the flag is
-`--dynamic-port-range 8000-8100`, the QUIC TPU port is `8009`.
+TPU port of that host. The QUIC TPU port for a leader can be identified by
+making an RPC call to [getClusterNodes](/docs/rpc/http/getClusterNodes.mdx).
 
 The peering would looking like the following: