[ProfileAPI] Returns code 500 after sending POST or PUT request without body

Description

Steps to reproduce

1. Send a Put request to update the profile without a request body. For example:

https://profilesapi-westus01.profilestore.episerver.net/api/v1.0/profiles/abc

Result 1: Returns a 500 Server error occurred

2. Send a Post request to create a profile without a request body. For example

https://profilesapi-westus01.profilestore.episerver.net/api/v1.0/profiles/

Result 2: Returns a 500 Server error occurred

Note that "without request body" means nothing in the request body. If request body is {}, the problem does not happen.