Update repositories.txt (#5294)

Add uMessagesBrokerLib

Author: Naguissa

repositories.txt

@@ -4316,6 +4316,7 @@ https://github.com/Naguissa/uTimerLib
 https://github.com/Naguissa/uTimerBrokerLib
 https://github.com/Naguissa/uUnixDate
 https://github.com/Naguissa/uHexLib
+https://github.com/Naguissa/uMessagesBrokerLib
 https://github.com/naiithink/musicians-mate
 https://github.com/nailujx86/ESP8266_multipart
 https://github.com/namino-cc/Namino_Library