fix bug in W5500 code

lib/WebServer/src/hardware/W5500EthClient.cpp

@@ -23,7 +23,36 @@ int W5500EthClient::setTimeout(uint32_t seconds)
 
 size_t W5500EthClient::write(const char *buffer, size_t size)
 {
-    return _ethClient->write(buffer, size);
+    if(size == 0)
+    {
+        return 0;
+    }
+
+    const size_t chunkSize = 2048; // W5100.SSIZE in socket.cpp
+
+    uint32_t index = 0;
+    uint32_t bytesLeft = 0;
+    size_t written = 0;
+
+    do
+    {
+        bytesLeft = size - index;
+        if(bytesLeft >= chunkSize)
+        {
+            _ethClient->write(&buffer[index], chunkSize);
+            index = index + chunkSize;
+            written = written + chunkSize;
+        }
+        else
+        {
+            _ethClient->write(&buffer[index], bytesLeft);
+            index = index + bytesLeft;
+            written = written + bytesLeft;
+        }
+    } while (bytesLeft > 0);
+
+    return written;
+//    return _ethClient->write(buffer, size);
 }
 
 IPAddress W5500EthClient::localIP()