Fix broken static-analysis on master

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/32436 introduced
the atlassian-jwt gem as part of the jira-ruby dependency update. To get
around this, we remove the constants as they have already been defined
by the gem.

ee/lib/atlassian/jwt.rb

@@ -8,9 +8,6 @@ require 'digest'
 module Atlassian
   module Jwt
     class << self
-      CANONICAL_QUERY_SEPARATOR = '&'
-      ESCAPED_CANONICAL_QUERY_SEPARATOR = '%26'
-
       def decode(token, secret, validate = true, options = {})
         options = { algorithm: 'HS256' }.merge(options)
         ::JWT.decode(token, secret, validate, options)