cce: enroll against broker.cce.dkfz.de

The CCE broker is live at broker.cce.dkfz.de, so the test broker at
test-no-real-data.broker.samply.de is no longer the CCE broker.
BROKER_ID roots the Beam PKI namespace, so this moves the proxy id to
cce-master.broker.cce.dkfz.de and the app ids derived from it --
cce/root.crt.pem still pins the old broker's CA and must be replaced
with the new one, and the proxy has to be re-enrolled before the
bridgehead connects again.

cce/vars

@@ -1,4 +1,4 @@
-BROKER_ID=test-no-real-data.broker.samply.de
+BROKER_ID=broker.cce.dkfz.de
 BROKER_URL=https://${BROKER_ID}
 PROXY_ID=${SITE_ID}.${BROKER_ID}
 FOCUS_BEAM_SECRET_SHORT="$(cat /proc/sys/kernel/random/uuid | sed 's/[-]//g' | head -c 20)"