files_external:notify selfTest breaks first event

[ariselseng]

Steps to reproduce

1. Use official nextcloud image with smbclient installed
2. Mount smb storage
3. Track changes with occ files_external:notify ID -v
4. run on a machine with the smb share mounted directly (without nextcloud):

$  touch SHARE/test.txt
$  touch SHARE/test2.txt

Expected behaviour

Both test.txt and test2.txt should be listed in the output of occ files_external:notify

Actual behaviour

Only test2.txt gets outputted (and registered in the database)

When I comment out this line it goes away and expected behaviour starts: https://github.com/nextcloud/server/blob/master/apps/files_external/lib/Command/Notify.php#L140