Lack of Support for Depreciated xhr-src

[mandatoryprogrammer]

While using this library in another project I noticed it throws a ValueError when a CSP makes use of the xhr-src directive.

According to MDN:

Prior to Firefox 23, xhr-src was used in place of the connect-src directive and only restricted the use of XMLHttpRequest.

Any interest in adding support for this?

[moloch--]

Yea, need to add CSP level 2 headers too.