[turba] Turba H5 (4.2.0alpha1)

[SSRI]

>> While using horde-db-migrate,
>>
>> [  INFO  ] Current turba schema version: 9
>> Migrating to TurbaUpgradeCategoriesToTags (10)
>> == 10 TurbaUpgradeCategoriesToTags: migrating
>> =================================
>> == 10 TurbaUpgradeCategoriesToTags: Migrating contact categories to
>> tags. =====
>> -- select('SELECT object_uid, object_category, owner_id FROM turba_objects')
>>    -> 0.0006s
>> == 10 TurbaUpgradeCategoriesToTags: Contact categories successfully
>> migrated. =
>> -- removeColumn('turba_objects', 'object_category')
>>    -> 23.0589s
>> == 10 TurbaUpgradeCategoriesToTags: migrated (506.2149s)
>> ======================
>>
>> we get the following errors in the logs :
>>
>> 2014-06-02T10:05:01+02:00 ERR: HORDE [horde] Share name user1 not
>> found [pid 14012 on line 199 of
>> "/usr/share/horde/pear/php/Horde/Share/Base.php"]
>> 2014-06-02T10:05:01+02:00 ERR: HORDE [horde] Share name user2 not
>> found [pid 14012 on line 199 of
>> "/usr/share/horde/pear/php/Horde/Share/Base.php"]
>> 2014-06-02T10:05:01+02:00 ERR: HORDE [horde] Share name user3 not
>> found [pid 14012 on line 199 of
>> "/usr/share/horde/pear/php/Horde/Share/Base.php"]
>> 2014-06-02T10:05:01+02:00 ERR: HORDE [horde] Share name user4 not
>> found [pid 14012 on line 199 of
>> "/usr/share/horde/pear/php/Horde/Share/Base.php"]
>>
>> Turba works fine after the database migration.
>>
>> Where this error is coming from ?
>
> These are probably from orphaned contacts in your database and can ignored.
>

OK.
Is there a way to safely delete these orphaned contacts ?