message: doc: fix send_transaction RPC doc
diff: @@ -351,7 +351,6 @@ Creates new transaction.
  transaction - The transaction object.
  version - Transaction version.
  - valid_since - Transaction valid_since.
  deps - Dependent cells.
  inputs - Transaction inputs.
  outputs - Transaction outputs.
  @@ -359,7 +358,7 @@ transaction - The transaction object.
  ## Examples
  ```shell
  -curl -d '{"id": 2, "jsonrpc": "2.0", "method":"send_transaction","params": [{"version":0, "deps":[], "inputs":[{"previous_output": {"hash": "<hash>", "index": 0}, "args": ["<unlock sign>"]}], "outputs":[{"capacity": 200, "data": "0x", "lock": {"version": 0, "args": [], "binary_hash": "0x0000000000000000000000000000000000000000000000000000000000000000"}, "type": null }]}]}' -H 'content-type:application/json' 'http://localhost:8114'
  +curl -d '{"id": 2, "jsonrpc": "2.0", "method":"send_transaction","params": [{"version":0, "deps":[], "inputs":[{"previous_output": {"hash": "<hash>", "index": 0}, "args": ["<unlock sign>"], "valid_since": 0}], "outputs":[{"capacity": 200, "data": "0x", "lock": {"version": 0, "args": [], "binary_hash": "0x0000000000000000000000000000000000000000000000000000000000000000"}, "type": null }]}]}' -H 'content-type:application/json' 'http://localhost:8114'
  ```
  ```json
  