Refactor matterbridge profile

- reduce pillar calls
- no longer define possible configuration options, apply settings from
  pillar 1:1

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

salt/profile/matterbridge/init.sls

@@ -1,5 +1,5 @@
 {%- set mypillar = salt['pillar.get']('profile:matterbridge') -%}
-{%- set instances = mypillar['instances'] | default([]) -%}
+{%- set instances = mypillar['instances'] or [] -%}
 
 matterbridge_packages:
   pkg.installed: