Fix etag route misses

Fixes gitlab-org/gitlab-ce#33106

app/models/environment.rb

@@ -209,7 +209,8 @@ class Environment < ActiveRecord::Base
   def etag_cache_key
     Gitlab::Routing.url_helpers.namespace_project_environments_path(
       project.namespace,
-      project)
+      project,
+      format: :json)
   end
 
   private

lib/gitlab/etag_caching/store.rb

@@ -25,8 +25,8 @@ module Gitlab
       end
 
       def redis_key(key)
-        raise 'Invalid key' unless Gitlab::EtagCaching::Router.match(key)
-        
+        raise 'Invalid key' if !Rails.env.production? && !Gitlab::EtagCaching::Router.match(key)
+
         "#{REDIS_NAMESPACE}#{key}"
       end
     end