Merge "according to rfc2617, nc-value = 8LHEX"

        String A2 = mMethod  + ":" + mUrl;

        // because we do not preemptively send authorization headers, nc is always 1

        String nc = "000001";

        String nc = "00000001";

        String cnonce = computeCnonce();

        String digest = computeDigest(A1, A2, nonce, QOP, nc, cnonce);