register.json 404 in gitlab logs

I run gitlab-ci-multi-runner (version 1.0.2 ea19241f) with following config:

concurrent = 4

[[runners]]
  name = "ei-grad"
  url = "https://git.edadev.ru/ci"
  token = "XXXXXXXXXXXXXXXXXXXXXXXXXXX"
  tls-ca-file = ""
  executor = "shell"
  environment = ["ANDROID_HOME=/opt/android-sdk"]

This results in periodic (1 per second) messages in Gitlab CE docker container log messages:

==> /var/log/gitlab/nginx/gitlab_access.log <==
87.250.245.170 - - [08/Feb/2016:08:19:17 +0000] "POST /ci/api/v1/builds/register.json HTTP/1.1" 404 27 "-" "Go 1.1 package http"

==> /var/log/gitlab/gitlab-rails/production.log <==
Started POST "/ci/api/v1/builds/register.json" for 87.250.245.170 at 2016-02-08 08:19:20 +0000

Besides this spam in logs all is fine - that runner works, I see it in Gitlab admin panel, it runs builds, all is ok.

If I stop this runner - the messages flow stops.