[stable18] set the mount id before calling storage wrapper

[backportbot-nextcloud]

backport of #22517

[faily-bot]

🤖 beep boop beep 🤖

Here are the logs for the failed build:

Status of 32482: failure

mariadb10.4-php7.3

Show full log

There were 2 warnings:
1) Test\Files\ViewTest::testRenameFailDeleteTargetKeepSource
Trying to configure method "writeStream" which cannot be configured because it does not exist, has not been specified, is final, or is static
2) Test\Files\ViewTest::testCopyFailDeleteTargetKeepSource
Trying to configure method "writeStream" which cannot be configured because it does not exist, has not been specified, is final, or is static
--
There was 1 failure:
1) Test\User\DatabaseTest::testSearch
Failed asserting that actual size 3 matches expected size 2.
/drone/src/tests/lib/User/Backend.php:114
/drone/src/tests/lib/User/DatabaseTest.php:125