Fix SQL type error

[jzombi]

Fixing the following SQL error encountered with PostgreSQL:

SQLSTATE[42883]: Undefined function: 7 ERROR:
No operator matches the given name and argument types. You might need to add explicit type casts.

This prevented the Nextcloud apps/files page to show the files and directories. See #27881

[kesselb]

server/core/Migrations/Version13000Date20170718121200.php

Lines 846 to 850 in 0447b53

	$table->addColumn('object_id', 'string', [
	'notnull' => true,
	'length' => 64,
	'default' => '',
	]);

object_id seems a string. Sounds good to use PARAM_STR_ARRAY here.

[solracsf]

Makes sense 👍

[welcome]

Thanks for your first pull request and welcome to the community! Feel free to keep them coming! If you are looking for issues to tackle then have a look at this selection: https://github.com/nextcloud/server/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22

[szaimen]

/backport to stable22