TT#42659 Another attempt to fix for "Delete" button in repoapi docker info page

Commit 39744330b3 wrongly added code to call
request.delete() with more than one argument:

  response = requests.delete(url, headers)
  TypeError: delete() takes 1 positional argument but 2 were given

Change-Id: I65b82d9ccef33b295d009b00461f9eeca2da0827

release_dashboard/utils/docker.py

@@ -82,7 +82,7 @@ def delete_docker_info(url):
         logger.debug("trigger: %s", url)
         headers = {'accept':
                    'application/vnd.docker.distribution.manifest.v2+json'}
-        response = requests.delete(url, headers)
+        response = requests.delete(url)
         logger.debug("response: %s" % response)
         response.raise_for_status()
         return