Actually merge the context variables into log entries

Without this processors, HTTP access logs look like this:

    [info] 127.0.0.1:44936 PUT /build 1.1 404 9 3170 [http.server]

With the change applied, they become more informative:

    [info] 127.0.0.1:44936 PUT /build 1.1 404 9 3170 [http.server] http_port=6040 known_worker=False worker_id=None

Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>

obs_proxy/utils.py

@@ -59,6 +59,7 @@ def configure_logging():
     timestamper = structlog.processors.TimeStamper(fmt="%Y-%m-%dT%H:%M:%SZ", utc=True)
     shared_processors = [
         structlog.stdlib.add_log_level,
+        structlog.contextvars.merge_contextvars,
         timestamper,
     ]