Not to pass the engine param if present

Change-Id: I841e8d0aad0892fddfd34bfc27936403a46243f6
diff --git a/salt/files/_engine.conf b/salt/files/_engine.conf
index ac0d328..7d80849 100644
--- a/salt/files/_engine.conf
+++ b/salt/files/_engine.conf
@@ -2,5 +2,7 @@
 
 engines:
 {%- for engine_name, engine in master.engine.items() %}
-- {{ engine.get('engine', engine_name) }}: {{ engine|yaml }}
+{%- set name = engine.get('engine', engine_name) %}
+{%- if engine.engine is defined %}{%- do engine.pop('engine') %}{% endif %}
+- {{ name }}: {{ engine|yaml }}
 {%- endfor %}