protocol mismatch error on https

when I'm on an https page in Chrome (and occasionally in Firefox) I am thrown a console error about a protocol mismatch. The maps.googleapis.com/maps/api/js?sensor=false script is blocked because of insecure content.

perhaps the protocol can be stripped from line 323 and 328 of google_map_field.module. I've tested this in chrome, safari, FF, and IE (9 & 10).

function google_map_field_add_maps_api() {
  if (variable_get('google_map_field_apikey', '') != '') {
    $element = array(
      '#type' => 'markup',
      '#markup' => '<script type="text/javascript" src="//maps.googleapis.com/maps/api/js?sensor=false&key=' . variable_get('google_map_field_apikey', '') . '"></script>',
    );
    drupal_add_html_head($element, 'google_maps_api');
  }
  else {
    drupal_add_js('//maps.googleapis.com/maps/api/js?sensor=false', 'external');
  }
}