ensure checkbox imports work on contacts

See #3850

CRM/Contact/Import/Parser/Contact.php

@@ -420,12 +420,7 @@ class CRM_Contact_Import_Parser_Contact extends CRM_Import_Parser {
               if ((strtolower($v2['label']) == strtolower(trim($v1))) ||
                 (strtolower($v2['value']) == strtolower(trim($v1)))
               ) {
-                if ($htmlType == 'CheckBox') {
-                  $params[$key][$v2['value']] = $formatted[$key][$v2['value']] = 1;
-                }
-                else {
-                  $params[$key][] = $formatted[$key][] = $v2['value'];
-                }
+                $params[$key][] = $formatted[$key][] = $v2['value'];
               }
             }
           }