Fixes the following traceback:
```
Failed to read config file: /quay-registry/conf/gunicorn_web.py
Traceback (most recent call last):
File "/usr/local/lib/python3.6/site-packages/gunicorn/app/base.py", line 111, in get_config_from_filename
spec.loader.exec_module(mod)
File "<frozen importlib._bootstrap_external>", line 678, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "/quay-registry/conf/gunicorn_web.py", line 21, in <module>
workers = get_worker_count("web", 2, minimum=2, maximum=32)
File "/quay-registry/util/workers.py", line 32, in get_worker_count
return max(override_value, minimum)
TypeError: '>' not supported between instances of 'int' and 'str'
```