Fix 2fa auth for dsm 7

[mib1185]

Beginning with DSM 7 a new version of SYNO.API.Auth was introduced - version 7.
In case of 2fa auth device ID to skip OTP checking is responded as device_id (not did):

DSM 7 (api version 7)

DEBUG: Request url: http://192.168.100.10:5000/webapi/entry.cgi?account=******&passwd=********&enable_device_token=yes&device_name=******&format=sid&otp_code=012345&api=SYNO.API.Auth&version=7&method=login
DEBUG: Request status_code: 200
DEBUG: Request headers: {'Server': 'nginx', 'Date': 'Sat, 10 Apr 2021 20:22:17 GMT', 'Content-Type': 'application/json; charset="UTF-8"', 'Transfer-Encoding': 'chunked', 'Connection': 'keep-alive', 'Keep-Alive': 'timeout=20', 'Vary': 'Accept-Encoding', 'P3P': 'CP="IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT"', 'X-Content-Type-Options': 'nosniff, nosniff', 'X-XSS-Protection': '1; mode=block, 1; mode=block', 'Set-Cookie': 'did=q0YtE1dlwUWJWtX2UUMbf7l4pbdtvKWEGH3tJjpxfc2t4oUeAw2g5cKjAB-QfLGx6ncZGuteJZEHAKfiYax_Nw;expires=Mon, 10-May-2021 20:22:17 GMT;path=/;HttpOnly', 'Cache-Control': 'max-age=0, no-cache, no-store, must-revalidate', 'Pragma': 'no-cache', 'Expires': '0', 'Content-Encoding': 'gzip'}
DEBUG: Request Method: GET
DEBUG: Successful returned data
DEBUG: API: SYNO.API.Auth
DEBUG: RESPONSE: {'data': {'account': 'hass', 'device_id': 'q0YtE1dlwUWJWtX2UUMbf7l4pbdtvKWEGH3tJjpxfc2t4oUeAw2g5cKjAB-QfLGx6ncZGuteJZEHAKfiYax_Nw', 'ik_message': '', 'is_portal_port': False, 'sid': '4fTalf67x6P__2vQO76czw5me1oQbRsszAIlLzTY3bQlAO-RUXsxYquIpkSj5XZ2M0WAF8cbQ108PQQG3J0vl0', 'synotoken': '--------'}, 'success': True}
DEBUG: Authentication successful, token: 4fTalf67x6P__2vQO76czw5me1oQbRsszAIlLzTY3bQlAO-RUXsxYquIpkSj5XZ2M0WAF8cbQ108PQQG3J0vl0