base: rsyslog force incoming as default ruleset

roles/base/templates/rsyslog.conf.j2

@@ -75,6 +75,10 @@ ruleset(name="incoming") {
   )
 }
 
+# The 'imklog' module before rsyslog 8.2008 always uses the default ruleset.
+# Force 'incoming' as the default ruleset to catch kernel messages as well.
+$DefaultRuleset incoming
+
 # Use the journald syslog forwarding socket, instead of reading
 # directly from the journal via the imjournal module. Some of the
 # reasons for this are mentioned in