Add submission # 6911

#6911

Author: ArduinoBot

registry.txt

@@ -8372,3 +8372,4 @@ https://github.com/ayresnet/AyresShell.git|Contributed|AyresShell
 https://github.com/7semi-solutions/7Semi-ADS1xx5-Arduino-Library.git|Contributed|7Semi_ADS1xx5
 https://github.com/tomrodinger/Servomotor_Arduino_Library.git|Contributed|Servomotor
 https://github.com/PhoenixSmaug/AFMotor-Shield-R4-Compatible.git|Contributed|Adafruit Motor Shield R4 Compatible
+https://github.com/csu333/TFTPClient.git|Contributed|TFTPClient