dnf-automatic: do not update kernels on armv7 builders, security update or no security update.

Signed-off-by: Kevin Fenzi <kevin@scrye.com>

roles/dnf-automatic/templates/automatic.conf.j2

@@ -49,4 +49,8 @@ email_host = localhost
 
 # Use this to filter DNF core messages
 debuglevel = 1
-
+{% if ansible_architecture == 'armv7l' %}
+# On arm builders do NOT update the kernel.
+# See https://bugzilla.redhat.com/show_bug.cgi?id=1576593
+exclude = kernel*
+{% endif %}