Rename to gunicorn.conf.py

This is the default since 17.5 (2013-07-03), and gunicorn starts with a
warning if it doesn't end in .py

Dockerfile

@@ -38,4 +38,4 @@ RUN PHONES_ENABLED=True \
 
 ENTRYPOINT ["/app/.local/bin/gunicorn"]
 
-CMD ["--config", "gunicorn.conf", "privaterelay.wsgi:application"]
+CMD ["--config", "gunicorn.conf.py", "privaterelay.wsgi:application"]

gunicorn.conf

@@ -1,11 +0,0 @@
-import os
-
-
-for k,v in os.environ.items():
-    if k.startswith('GUNICORN_'):
-        key = k.split('_', 1)[1].lower()
-        locals()[key] = v
-
-
-if 'PORT' in os.environ:
-    locals()['bind'] = '0.0.0.0:%s' % os.environ['PORT']

gunicorn.conf.py

@@ -0,0 +1,10 @@
+import os
+
+for k, v in os.environ.items():
+    if k.startswith("GUNICORN_"):
+        key = k.split("_", 1)[1].lower()
+        locals()[key] = v
+
+
+if "PORT" in os.environ:
+    locals()["bind"] = "0.0.0.0:{}".format(os.environ["PORT"])