When parsing image envs we need to be strict about the format, only the
"key=value" format must be accepted. Just keys must be rejected as they
are not valid according to the image spec.
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
(cherry picked from commit 6c431b73db)
Signed-off-by: Paul Holzinger <pholzing@redhat.com>