www/nginx: Update to 1.20.1

PR: 256172
Reported by: Christos Chatzaras <chris@cretaforce.gr>
Reviewed by: garga
Approved by: maintainer timeout
MFH: 2021Q2
Security: 0882f019-bd60-11eb-9bdd-8c164567ca3c
Sponsored by: Rubicon Communications, LLC ("Netgate")