RELEASES.md: v1.2 reached EOL on October 15, 2020
RELEASES.md: v1.2 reached EOL on October 15, 2020

The file was not updated to reflect the current status.

Signed-off-by: Akihiro Suda <10ddef0dea2a66ab193b07198faa879adcb213d8@hco.ntt.co.jp>

containerd/containerd,dmcgowan/containerd,mikebrow/containerd,containerd/containerd,estesp/containerd,estesp/containerd,thaJeztah/containerd,vdemeester/containerd,thaJeztah/containerd,mikebrow/containerd,vdemeester/containerd,dmcgowan/containerd