superset login is not working when Transfer encoding set to chunked in http request

[nishantmonu51]

I am trying to use superset behind a proxy server, where the proxy server is using chunked encoding in requests. After debugging for a while found that when using chunked encoding the login request ignores the request content.

Make sure these boxes are checked before submitting your issue - thank you!

• [*] I have checked the superset logs for python stacktraces and included it here as text if any
• [*] I have reproduced the issue with at least the latest released version of superset
• [*] I have checked the issue tracker for the same issue and I haven't found one similar

Superset version

0.14.1

Expected results

Actual results

Steps to reproduce

disable CSRF by setting WTF_CSRF_ENABLED to false.

1. try to login via curl below command works and login works fine-
   curl -X POST 'http://superset-ip:port/login/' --data 'csrf_token=None&username=admin&password=admin’

2. set encoding to chunked , now login will not work -
   curl -X POST 'http://superset-ip:port/login/' -H 'Transfer-Encoding: chunked' --data 'csrf_token=None&username=admin&password=admin'