Fix warning during test
Fix warning during test

Fixes warning output:

DeprecationWarning: "charset" is deprecated. Use "encoding" instead

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