Using cfg_salt['master'] is never the right answer

- When it's iterable, the minion could be running on the master
- When it's a string, there's no advantage over just specifying
  `salt:minion:master`

salt/files/minion.d/f_defaults.conf

@@ -20,8 +20,7 @@
 {{ get_config('default_include', 'minion.d/*.conf') }}
 
 # master configs
-{%- if 'master' in cfg_minion -%}
-{%- if cfg_minion['master'] is not string %}
+{%- if 'master' in cfg_minion and cfg_minion['master'] is not string %}
 master:
   {% for name in cfg_minion['master'] -%}
   - {{ name }}
@@ -29,16 +28,6 @@ master:
 {%- else %}
 {{ get_config('master', 'salt') }}
 {%- endif %}
-{% elif 'master' in cfg_salt -%}
-{%- if cfg_salt['master'] is not string %}
-master:
-  {% for name in cfg_salt['master'] -%}
-  - {{ name }}
-  {% endfor -%}
-{%- else %}
-{{ get_config('master', 'salt') }}
-{%- endif -%}
-{%- endif %}
 
 # choose a random master
 {{ get_config('random_master', 'False') }}