Fixed wrong data type declaration

[demis-palma]

$current_update is declared as JUpdate, but actually it's a JTableUpdate instead.
If it was a JUpdate, the subsequent calls to properties $current_update->extra_query and $current_update->version would cause a fatal error, since they are protected properties.

It can be verified with the help of a the debugger.

[zero-24]

Is this the actual type? As we just return arrays in that method?

https://github.com/joomla/joomla-cms/blob/staging/libraries/joomla/updater/adapters/collection.php#L253

https://github.com/joomla/joomla-cms/blob/staging/libraries/joomla/updater/adapters/extension.php#L357

[mbabker]

Yes that is correct. update_sites is an array of associative arrays and updates is an array of JTableUpdate instances.

[wilsonge]

Dunno if someone wants to amend the class properties in those two classes to be JTableUpdate[]