Error processing empty client nonce in digest auth

[endragor]

There is an error in Digest.prototype.parseAuthHeader:

var tokens = searchHeader.match(/(\w+)="([^"]+)"/g);

means that auth parameter values can't be empty but client actually might send empty cnonce which will result in undefined (instead of being empty) cnonce variable on server side.

[gevorg]

Issue is fixed and pushed with 1.2.3 version. I published it to NPM as well. Thanks, Gevorg.