fix typo in help text

'in which the transaction is included in'

src/rpc/rawtransaction.cpp

@@ -211,7 +211,7 @@ UniValue gettxoutproof(const UniValue& params, bool fHelp)
             "\nNOTE: By default this function only works sometimes. This is when there is an\n"
             "unspent output in the utxo for this transaction. To make it always work,\n"
             "you need to maintain a transaction index, using the -txindex command line option or\n"
-            "specify the block in which the transaction is included in manually (by blockhash).\n"
+            "specify the block in which the transaction is included manually (by blockhash).\n"
             "\nReturn the raw transaction data.\n"
             "\nArguments:\n"
             "1. \"txids\"       (string) A json array of txids to filter\n"