improve ram usage on one char send

Author: Links2004

src/SocketIOclient.cpp

@@ -42,7 +42,7 @@ void SocketIOclient::runCbEvent(WStype_t type, uint8_t * payload, size_t length)
         case WStype_CONNECTED: {
             DEBUG_WEBSOCKETS("[wsIOc] Connected to url: %s\n", payload);
             // send message to server when Connected
-            // socket.io upgrade confirmation message (required)
+            // Engine.io upgrade confirmation message (required)
             sendTXT(eIOtype_UPGRADE);
         }
             break;

src/WebSocketsClient.cpp

@@ -216,7 +216,9 @@ bool WebSocketsClient::sendTXT(String & payload) {
 }
 
 bool WebSocketsClient::sendTXT(char payload) {
-    return sendTXT((uint8_t *) &payload, 1);
+    uint8_t buf[WEBSOCKETS_MAX_HEADER_SIZE + 2] = {0x00};
+    buf[WEBSOCKETS_MAX_HEADER_SIZE] = payload;
+    return sendTXT(buf, 1, true);
 }
 
 /**