erro updates

Using configuration file /home/root/servidor/etc/worldserver.conf.
Using SSL version: OpenSSL 1.0.1f 6 Jan 2014 (library: OpenSSL 1.0.1f 6 Jan 2014)
Using Boost version: 1.54.0
Updating Auth database…
>> Auth database is up-to-date! Containing 2 new and 8 archived updates.
Updating Character database…
>> Character database is up-to-date! Containing 1 new and 12 archived updates.
Updating World database…
>> Reapplying update “2015_12_20_00_world.sql” ‘88C8D50’ → ‘CD45E89’ (it changed)…
ERROR 1062 (23000) at line 3: Duplicate entry ‘79520’ for key ‘PRIMARY’

Applying of file ‘/home/TrinityCore/sql/updates/world/2015_12_20_00_world.sql’ to database ‘world’ failed! If you are an user pull the latest revision from the repository. If you are a developer fix your sql query.
Could not update the World database, see log for details.

Ubuntu 14.04
TrinityCore db version: 60

Try updating your core.