upgrade alpine base image v3.12->3.13.1 including upgrade of openssh-server package v8.3_p1-r1->8.4_p1-r2 & rsync package v3.1.3-r3->3.2.3-r1 (diff links below)
https://www.openssh.com/txt/release-8.4
https://git.alpinelinux.org/aports/commit/main/openssh?id=271a173d27e313f80d3c0a7c0c0e4b9060e55e6d
https://git.alpinelinux.org/aports/commit/main/openssh?id=be38ca6bc1abd987c47227b7b0025e12c39dcbfa
https://git.alpinelinux.org/aports/commit/main/openssh?id=ec4425ce83436793a42ac9784b717644fe05479a
https://download.samba.org/pub/rsync/NEWS#3.2.0
https://download.samba.org/pub/rsync/NEWS#3.2.1
https://download.samba.org/pub/rsync/NEWS#3.2.2
https://download.samba.org/pub/rsync/NEWS#3.2.3
https://git.alpinelinux.org/aports/commit/main/rsync?id=725ac7fb785f7eeba7b0e65d6701fb9e79e456d2
https://git.alpinelinux.org/aports/commit/main/rsync?id=bff3e557e3f345e8542d9d309cb1719d3453d1ea
https://git.alpinelinux.org/aports/commit/main/rsync?id=41ac90c36c91b15d940cd8c4a41e9126b49b0646
https://git.alpinelinux.org/aports/commit/main/rsync?id=dc22b5a707680d1cf59dbe5e20f23b7617529c93