Remove double quotes from variable

[Raghu nathan]

We are calling %{Module-Failure-Message} in linelog and trying to create
JSON logs.

But we are getting sometime error with double quotes, which is creating
issue on JSON spec.

For example,
In linelog messages we have below entry

Access-Reject = "{\"Datetime\":\"%t\",\
\"Packet-Type\":\"%{reply:Packet-Type}\",\
\"User-Name\":\"%{User-Name}\",\
\"Module-Failure-Message\":\"%{Module-Failure-Message}\"\
                }"
We are getting the logs as

{"Datetime":"Fri Oct 26 09:07:17
2018","Packet-Type":"Access-Reject","User-Name":"CONSUMER4.TATA","Module-Failure-Message":"pap:
Cleartext password "WRONG-PASSWORD" does not match "known good" password"}


In the Module-Failure-Message output we are receiving the message with
double quotes which is not as per JSON standard.
Please let me know how I can solve the issue without doing any coding.

Regards,
Raghu.