add engines as a reserved_keys to not add generic configuration

salt/files/master.d/f_defaults.conf

 # This file managed by Salt, do not edit by hand!!
 # Based on salt version 2015.8.7 default config
-{% set reserved_keys = ['master', 'minion', 'cloud', 'salt_cloud_certs'] -%}
+{% set reserved_keys = ['master', 'minion', 'cloud', 'salt_cloud_certs', 'engines'] -%}
 {% set cfg_salt = pillar.get('salt', {}) -%}
 {% set cfg_master = cfg_salt.get('master', {}) -%}
 {%- macro get_config(configname, default_value) -%}

salt/files/minion.d/f_defaults.conf

 # This file managed by Salt, do not edit by hand!!
 #  Based on salt version 2015.8.7 default config
 #
-{% set reserved_keys = ['master', 'minion', 'cloud', 'salt_cloud_certs'] -%}
+{% set reserved_keys = ['master', 'minion', 'cloud', 'salt_cloud_certs', 'engines'] -%}
 {% set cfg_salt = pillar.get('salt', {}) -%}
 {% set cfg_minion = cfg_salt.get('minion', {}) -%}
 {% set default_keys = [] -%}
 {%- if configname not in reserved_keys and configname not in default_keys %}
 {{ configname }}: {{ cfg_minion[configname]|json }}
 {%- endif %}
-{%- endfor %}
+{%- endfor %}