Update docker-build steps in Makefile.release (#1200)
Update docker-build steps in Makefile.release (#1200)

* Update docker-build steps in Makefile.release

for different architectures

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>

* Update to use `case ... esac` in shell script

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>

* Remove `RUN` cmd in Dockerfile in case of non amd64 CPU

ssl will only be supported on amd64 CPUs for now.

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>

miekg/coredns,yongtang/coredns,jremond/coredns,ii/coredns,johnbelamaric/coredns,jremond/coredns,ii/coredns,coredns/coredns,miekg/coredns,chrisohaver/coredns,johnbelamaric/coredns