EDIT

/*

 * update funktions:

 *

 * - 1 digit for Drupal core compatibility.

 * - 1 digit for your module's major release version (e.g., is this the 7.x-1.* (1) or 7.x-2.* (2) series of your module?). This digit should be 0 for initial porting of your module to a new Drupal core API.

 * - 2 digits for sequential counting, starting with 00.

 */

/**

 * update function for RELEASE 3.13

 */

function cdm_dataportal_update_7301() {

  // reset edit_map_server variable to default

  variable_del('edit_map_server');

}