Update rpc port (#69)

docs/staking/validate.mdx

@@ -198,7 +198,7 @@ Save both seed phrases in a secure place. Skip the previous step if you intend t
 You need to tell the chain your Session keys. If you are on a remote server, it is easier to run this command on the same machine (while the node is running with the default HTTP RPC port configured):
 
 ```sh
-curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "author_rotateKeys", "params":[]}' http://localhost:9933
+curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "author_rotateKeys", "params":[]}' http://localhost:9944
 ```
 
 Output: