Add more optional fields to httpcheck plugin config

templates/httpcheck.conf

@@ -103,8 +103,14 @@ redirect: no
 {{ item.name|to_uuid }}:
     name: {{ item.name }}
     url: {{ item.url }}
+{% if item.method is defined %}
+    method: {{ item.method }}
+{% endif %}
+{% if item.body is defined %}
+    body: {{ item.body }}
+{% endif %}
 {% if item.regex is defined %}
-    regex: '{{ item.regex|regex_escape() }}'
+    regex: {{ item.regex|regex_escape() }}
 {% endif %}
 {% if item.redirect|default(false) %}
     redirect: yes