Send "Connection: close" HTTP header with JSON-RPC requests (client)

src/bitcoinrpc.cpp

@@ -1826,6 +1826,7 @@ string HTTPPost(const string& strMsg, const map<string,string>& mapRequestHeader
       << "Host: 127.0.0.1\r\n"
       << "Content-Type: application/json\r\n"
       << "Content-Length: " << strMsg.size() << "\r\n"
+      << "Connection: close\r\n"
       << "Accept: application/json\r\n";
     BOOST_FOREACH(const PAIRTYPE(string, string)& item, mapRequestHeaders)
         s << item.first << ": " << item.second << "\r\n";