added content-type header

tasks/main.yml

diff --git a/tasks/main.yml b/tasks/main.yml
index fe50861..ec534ca 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -22,6 +22,6 @@
     password: '{{ opdk_user_pass }}'
     method: POST
     url: http://{{ public_mgmt_ip }}:{{ ms_ext_mgmt_port }}/v1/servers/{{ uuid }}
-    body: reachable={{ reachable }}
+    body: 'reachable={{ reachable }}'
     HEADER_Content-type: 'application/x-www-form-urlencoded'
   when: uuid is defined
\ No newline at end of file