Dockerfile: use Go 1.5.3
Dockerfile: use Go 1.5.3

Go 1.5.2 is known to have security vulnerabilities in the standard
library. As such, we should use 1.5.3.

Signed-off-by: Aleksa Sarai <a8eb12d32d6ec07cdf737175ec7d4a0f1b4e1ee7@suse.de>

Wolphin-project/containerd,chanezon/containerd,hqhq/containerd,yuexiao-wang/containerd,kunalkushwaha/containerd,crosbymichael/containerd,dmcgowan/containerd,xiekeyang/containerd,thaJeztah/containerd,miaoyq/containerd,containerd/containerd,amitkris/containerd,vdemeester/containerd,mikebrow/containerd,docker/containerd,estesp/containerd,containerd/containerd,AkihiroSuda/containerd,vdemeester/containerd,mikebrow/containerd,thaJeztah/containerd,kunalkushwaha/containerd,crosbymichael/containerd,estesp/containerd,miaoyq/containerd,dmcgowan/containerd,amitkris/containerd,lichao-mobanche/containerd,rajasec/containerd