rewrite for efficiency

libi2pd_client/HTTPProxy.cpp

@@ -219,9 +219,11 @@ namespace proxy {
 		/* replace headers */
 		req.UpdateHeader("User-Agent", "MYOB/6.66 (AN/ON)");
 		/* add headers */
+		/* close connection, if not Connection: (U|u)pgrade (for websocket) */
 		auto h = req.GetHeader ("Connection");
-		if (h.find("upgrade") == std::string::npos && h.find("Upgrade") == std::string::npos)
-			req.UpdateHeader("Connection", "close"); /* close everything, except websocket */
+		auto x = h.find("pgrade"); 
+		if (!(x != std::string::npos && std::tolower(h[x - 1]) == 'u'))
+			req.UpdateHeader("Connection", "close");
 	}
 
 	/**

libi2pd_client/I2PTunnel.cpp

@@ -256,10 +256,12 @@ namespace client
 					{
 						if (!m_ConnectionSent && !line.compare(0, 10, "Connection"))
 						{
-							if (line.find("upgrade") == std::string::npos && line.find("Upgrade") == std::string::npos)
-								m_OutHeader << "Connection: close\r\n"; /* close everything, except websocket */
-							else
+							/* close connection, if not Connection: (U|u)pgrade (for websocket) */
+							auto x = line.find("pgrade"); 
+							if (x != std::string::npos && std::tolower(line[x - 1]) == 'u')
 								m_OutHeader << line << "\r\n";
+							else
+								m_OutHeader << "Connection: close\r\n";
 
 							m_ConnectionSent = true;
 						}