Drop Release label in favor of OSBS release_bump plugin.

OSBS can automatically bump the release number, for that
we just need to drop the label from the Dockerfile

See https://pagure.io/ContainerSIG/container-sig/issue/1

Signed-off-by: Clement Verna <cverna@tutanota.com>

Dockerfile

@@ -1,12 +1,11 @@
-FROM registry.fedoraproject.org/fedora:rawhide
+FROM registry.fedoraproject.org/fedora:28
 
 ENV container=docker FLANNELD_ETCD_ENDPOINTS="http://127.0.0.1:2379" FLANNELD_ETCD_PREFIX="/atomic.io/network"
 
-ENV VERSION=0 RELEASE=8 ARCH=x86_64
+ENV VERSION=0 ARCH=x86_64
 LABEL com.redhat.component="flannel" \
       name="$FGC/flannel" \
       version="$VERSION" \
-      release="$RELEASE.$DISTTAG" \
       architecture="$ARCH" \
       summary="An etcd driven address agent, intended to be run as a system container" \
       maintainer="Giuseppe Scrivano <gscrivan@redhat.com>" \