Fix frozen input by returning a new hash

lib/datadog/tracing/contrib/redis/patcher.rb

@@ -21,9 +21,7 @@ def self.included(base)
             # Instance method patch for redis instance
             module InstanceMethods
               def initialize(options = {})
-                options[:redis_instance] = self
-
-                super(options)
+                super(options.merge(redis_instance: self))
               end
             end
           end