Getting the headers from reference into a request call appends the headers. Doesn't overwrite it.

[Purva2710]

Sample Reference call
<template>
<baseurl>\</baseurl>
<headers>
{"Content-type":"${content-type}",
"Accept":"${accept}"}
</headers>
<paramters>
{"content-type":"application/json",
"accept":"application/json"}
</parameters>
</template>

Sample Request call
<reference>template</reference>
<method>POST</method>
<headers>
{"Content-type":"application/json",
"Accept":"application/json"}
</headers>

Expected result
Client out-bound request
POST https://<post url>
Content-type: application/json, Accept:application/json

Actual output
Client out-bound request
POST https://<post url>
Content-type: application/json, application/json, Accept: application/json, application.json

[cjayswal]

This issue is not reproducible with latest (3.0.0) version.