Update docker_healthcheck.py (#1882)

* Update docker_healthcheck.py

This does not (always) work. Sometimes, other JSON files appear in the directory, like this kernel-xxx file

jpserver-6.json
jpserver-6-open.html
kernel-374f4977-29fc-43e0-8a48-231f6980fdab.json

changing the glob expression to something like "jpserver*.json" instead of simply "*.json" should solve the problem (at least in my case, I checked with a quick patch on a live container, the healthcheck immediately turned 'healthy' again...)

* Update base-notebook/docker_healthcheck.py

* Update docker_healthcheck.py

---------

Co-authored-by: Ayaz Salikhov <mathbunnyru@users.noreply.github.com>

base-notebook/docker_healthcheck.py

@@ -11,7 +11,7 @@
 # As this is a healthcheck, it should succeed or raise an exception on error
 
 runtime_dir = Path("/home/") / os.environ["NB_USER"] / ".local/share/jupyter/runtime/"
-json_file = next(runtime_dir.glob("*.json"))
+json_file = next(runtime_dir.glob("*server-*.json"))
 
 url = json.loads(json_file.read_bytes())["url"]
 url = url + "api"