Update links to redis docs

Update code comments and one error message
that link to old location of moved doc

config/redis.cache.yml.example

@@ -26,7 +26,7 @@ production:
   # http://redis.io/topics/sentinel
   #
   # You must specify a list of a few sentinels that will handle client connection
-  # please read here for more information: https://docs.gitlab.com/ce/administration/high_availability/redis.html
+  # please read here for more information: https://docs.gitlab.com/ee/administration/redis/index.html
   ##
   # url: redis://master:6380
   # sentinels:

config/redis.queues.yml.example

@@ -26,7 +26,7 @@ production:
   # http://redis.io/topics/sentinel
   #
   # You must specify a list of a few sentinels that will handle client connection
-  # please read here for more information: https://docs.gitlab.com/ce/administration/high_availability/redis.html
+  # please read here for more information: https://docs.gitlab.com/ee/administration/redis/index.html
   ##
   # url: redis://master:6381
   # sentinels:

config/redis.shared_state.yml.example

@@ -26,7 +26,7 @@ production:
   # http://redis.io/topics/sentinel
   #
   # You must specify a list of a few sentinels that will handle client connection
-  # please read here for more information: https://docs.gitlab.com/ce/administration/high_availability/redis.html
+  # please read here for more information: https://docs.gitlab.com/ee/administration/redis/index.html
   ##
   # url: redis://master:6382
   # sentinels:

config/resque.yml.example

@@ -22,7 +22,7 @@ production:
   # http://redis.io/topics/sentinel
   #
   # You must specify a list of a few sentinels that will handle client connection
-  # please read here for more information: https://docs.gitlab.com/ce/administration/high_availability/redis.html
+  # please read here for more information: https://docs.gitlab.com/ee/administration/redis/index.html
   ##
   # url: redis://master:6379
   # sentinels:

lib/system_check/app/redis_version_check.rb

@@ -37,7 +37,7 @@ module SystemCheck
           @custom_error_message
         )
         for_more_information(
-          'doc/administration/high_availability/redis.md#provide-your-own-redis-instance'
+          'doc/administration/redis/index.html#redis-replication-and-failover-using-the-non-bundled-redis'
         )
         fix_and_rerun
       end