relvalconsumer: fix email error message subject

boy, Lukas is sure gonna have a nasty surprise in his inbox in
the morning.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

roles/relvalconsumer/templates/relvalconsumer.toml.j2

@@ -69,7 +69,7 @@ level = "ERROR"
 mailhost = "{{ relvalconsumer_amqp_smtp }}"
 fromaddr = "{{ relvalconsumer_amqp_mailfrom }}"
 toaddrs = [{% for key in relvalconsumer_amqp_mailto %}"{{ key }}",{% endfor %}]
-subject = "openQA scheduler error"
+subject = "relvalconsumer error"
 {% endif %}
 
 [log_config.loggers.RelvalConsumer]