updated env.sample

.env.sample

@@ -84,6 +84,7 @@
 # REDIS_PORT=6379
 # REDIS_DB=0
 # REDIS_AUTH=PLEASE_REPLACE_ME
+# REDIS_USER=megatron
 # number of items to read from Redis at a time
 # REDIS_READ_CHUNK_SIZE=1000
 # number of items to write from Redis at a time