Bump Pexip-Upstream to bullseye

Author: mhy-pexip

debian/control

@@ -15,7 +15,7 @@ Vcs-Git: https://salsa.debian.org/python-team/packages/python-redis.git
 Vcs-Browser: https://salsa.debian.org/python-team/packages/python-redis
 Homepage: https://github.com/andymccurdy/redis-py
 Rules-Requires-Root: no
-XS-Pexip-Upstream: http://ftp.debian.org/debian/ bullseye
+XS-Pexip-Upstream: http://deb.debian.org/debian/ bullseye
 
 Package: python3-redis
 Architecture: all