jobs/ttcn3: send mails to jenkins-notifications ML

Send the mails to the mailing list rather than to only Harald and me, so
it's less likely that failures go unnoticed in case we are both
unavailable.

Change-Id: I4fc554f0624e1ce98cafaf383132241365f1e4d9

jobs/ttcn3-testsuites.yml

@@ -476,7 +476,7 @@
           allow-empty-results: false
       - email:
           notify-every-unstable-build: true
-          recipients: laforge@gnumonks.org osmith@sysmocom.de
+          recipients: jenkins-notifications@lists.osmocom.org
           send-to-individuals: false
       - archive:
           allow-empty: false