doc: Remove outdated minrelaytxfee comment

contrib/devtools/check-doc.py

@@ -21,7 +21,7 @@ CMD_GREP_DOCS = r"egrep -r -I 'HelpMessageOpt\(\"\-[^\"=]+?(=|\")' %s" % (CMD_RO
 REGEX_ARG = re.compile(r'(?:map(?:Multi)?Args(?:\.count\(|\[)|Get(?:Bool)?Arg\()\"(\-[^\"]+?)\"')
 REGEX_DOC = re.compile(r'HelpMessageOpt\(\"(\-[^\"=]+?)(?:=|\")')
 # list unsupported, deprecated and duplicate args as they need no documentation
-SET_DOC_OPTIONAL = set(['-rpcssl', '-benchmark', '-h', '-help', '-socks', '-tor', '-debugnet', '-whitelistalwaysrelay', '-prematurewitness', '-walletprematurewitness', '-promiscuousmempoolflags', '-blockminsize', '-sendfreetransactions'])
+SET_DOC_OPTIONAL = set(['-rpcssl', '-benchmark', '-h', '-help', '-socks', '-tor', '-debugnet', '-whitelistalwaysrelay', '-prematurewitness', '-walletprematurewitness', '-promiscuousmempoolflags', '-blockminsize'])
 
 def main():
   used = check_output(CMD_GREP_ARGS, shell=True)

src/init.cpp

@@ -1030,14 +1030,7 @@ bool AppInitParameterInteraction()
     if (nConnectTimeout <= 0)
         nConnectTimeout = DEFAULT_CONNECT_TIMEOUT;
 
-    // Fee-per-kilobyte amount required for mempool acceptance and relay
-    // If you are mining, be careful setting this:
-    // if you set it to zero then
-    // a transaction spammer can cheaply fill blocks using
-    // 0-fee transactions. It should be set above the real
-    // cost to you of processing a transaction.
-    if (IsArgSet("-minrelaytxfee"))
-    {
+    if (IsArgSet("-minrelaytxfee")) {
         CAmount n = 0;
         if (!ParseMoney(GetArg("-minrelaytxfee", ""), n)) {
             return InitError(AmountErrMsg("minrelaytxfee", GetArg("-minrelaytxfee", "")));