SMS integration: Allow receiving SMS for surf sticks with web API (e.g. Huawei)

It would be helpful if the SMS integration could be updated to support receiving SMS with Huawei LTE surf sticks. This would require two changes:

  • Upgrade Gammu to 1.42
    • This is required to get support for the 5-parameter CNMI configuration
  • Allow setting the atgen_setcnmi configuration option

The configuration option follows the following pattern:

\d*(,\d*){0,4}

An empty string (or ,,,,) should mean that the configuration option is not used.