fix for alternate_names table with mysql strict mode

These tinyint columns don't have a suitable default value, so the inserts fail when strict mode is enabled
```
mysql> describe geonames_alternate_names;
+----------------+------------------+------+-----+---------+----------------+
| Field          | Type             | Null | Key | Default | Extra          |
+----------------+------------------+------+-----+---------+----------------+
| id             | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| name_id        | int(11)          | NO   | MUL | NULL    |                |
| iso_language   | varchar(7)       | NO   |     | NULL    |                |
| alternate_name | varchar(200)     | NO   |     | NULL    |                |
| is_preferred   | tinyint(1)       | NO   | MUL | NULL    |                |
| is_short       | tinyint(1)       | NO   | MUL | NULL    |                |
| is_colloquial  | tinyint(1)       | NO   | MUL | NULL    |                |
| is_historic    | tinyint(1)       | NO   |     | NULL    |                |
+----------------+------------------+------+-----+---------+----------------+
```


This fix works fine, but we should probably also include a migration to change the defaults to `0`