Sort SalesForceField Key Dropdown

There are a lot of field in this drop-down, it would help if it was sorted alphabetically.
Around line 86 salesforcewebform.module:

		  $valid_fields = array_merge($sfwaf_array, salesforcewebform_load_custom_fields('webform'));
// BEGIN NEW CODE
                  asort($valid_fields);
// END NEW CODE
		  $new_form_key = array(
				'#type' => 'select',
				'#title' => t('SalesForce Field Key'),
				'#multiple' => FALSE,
				'#options' => $valid_fields,
				'#description' => t('Select a SalesForce field that this form field will map to.  If you switch the form to an email for this will be used as the machine readable key.'),
				'#weight' => $form['field']['form_key']['#weight'],
				'#default_value' => empty($form['#parameters'][3]['form_key']) ? '' : $form['#parameters'][3]['form_key'],
		  );