Update YT Link

Author: alejandro-du

README.md

@@ -7,4 +7,4 @@ Learn about reactive programming with these projects:
  - See how to use the `Flux` class and [R2DBC](https://r2dbc.io/) to build a fully reactive service.
  - Compare the the throughput using [Artillery](https://www.artillery.io/). See how many HTTP 200 OK responses you get on each service (test scripts included on each service project).
 
- Follow me on [Twitter](https://twitter.com/alejandro_du) and subscribe to the [MariaDB](https://www.youtube.com/mariadb) and [Programming Brain](https://www.youtube.com/user/jaal2000) channels on YouTube!
+ Follow me on [Twitter](https://twitter.com/alejandro_du) and subscribe to the [MariaDB](https://www.youtube.com/mariadb) and [Programming Brain](https://www.youtube.com/ProgrammingBrain) channels on YouTube!