[RPC] Remove field in getblocktemplate help that has never been used

Author: conscott

src/rpc/mining.cpp

@@ -336,7 +336,6 @@ UniValue getblocktemplate(const JSONRPCRequest& request)
             "         \"fee\": n,                    (numeric) difference in value between transaction inputs and outputs (in satoshis); for coinbase transactions, this is a negative Number of the total collected block fees (ie, not including the block subsidy); if key is not present, fee is unknown and clients MUST NOT assume there isn't one\n"
             "         \"sigops\" : n,                (numeric) total SigOps cost, as counted for purposes of block limits; if key is not present, sigop cost is unknown and clients MUST NOT assume it is zero\n"
             "         \"weight\" : n,                (numeric) total transaction weight, as counted for purposes of block limits\n"
-            "         \"required\" : true|false      (boolean) if provided and true, this transaction must be in the final block\n"
             "      }\n"
             "      ,...\n"
             "  ],\n"