Update dependency uwsgi to v2.0.20

Author: renovate-bot

requirements.txt

@@ -25,6 +25,6 @@ retrying==1.3.3; python_version >= "2.7" and python_full_version < "3.0.0" or py
 six==1.15.0; python_full_version >= "3.6.1"
 sortedcontainers==2.3.0; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
 tenacity==6.2.0; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"
-uwsgi==2.0.19.1
+uwsgi==2.0.20
 webassets==2.0
 werkzeug==1.0.1; python_version >= "2.7" and python_full_version < "3.0.0" or python_full_version >= "3.5.0"