redis >= 5.0.1 changed behavior of XREADGROUP stream ID
redis >= 5.0.1 changed behavior of XREADGROUP stream ID

Redis versions 5.0.1 require messages to be read with the special ID '>'
when using XREADGROUP

Fixes #1073

redis/redis-py,mozillazg/redis-py-doc,alisaifee/redis-py,5977862/redis-py,andymccurdy/redis-py,5977862/redis-py,andymccurdy/redis-py,andymccurdy/redis-py,redis/redis-py,alisaifee/redis-py,5977862/redis-py,mozillazg/redis-py-doc