Do not fail if share for mountpoint is no longer available

[juliushaertl]

If the share for a mountpoint cannot be found in the oc_share_external table anymore, the elseif would still pass and then try to access $share even though it is false:

Exception during scan: Trying to access array offset on value of type bool
#0 /var/www/nextcloud/apps/files_sharing/lib/External/Manager.php(533): OCA\Files\Command\Scan->exceptionErrorHandler()
#1 /var/www/nextcloud/apps/files_sharing/lib/External/Storage.php(219): OCA\Files_Sharing\External\Manager->removeShare()
#2 [internal function]: OCA\Files_Sharing\External\Storage->checkStorageAvailability()
#3 /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php(507): call_user_func_array()
#4 [internal function]: OC\Files\Storage\Wrapper\Wrapper->__call()
#5 /var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php(507): call_user_func_array()
#6 /var/www/nextcloud/apps/files_sharing/lib/External/Scanner.php(90): OC\Files\Storage\Wrapper\Wrapper->__call()
#7 /var/www/nextcloud/apps/files_sharing/lib/External/Scanner.php(45): OCA\Files_Sharing\External\Scanner->scanAll()
#8 /var/www/nextcloud/lib/private/Files/Utils/Scanner.php(260): OCA\Files_Sharing\External\Scanner->scan()
#9 /var/www/nextcloud/apps/files/lib/Command/Scan.php(151): OC\Files\Utils\Scanner->scan()
#10 /var/www/nextcloud/apps/files/lib/Command/Scan.php(207): OCA\Files\Command\Scan->scanFiles()
#11 /var/www/nextcloud/3rdparty/symfony/console/Command/Command.php(255): OCA\Files\Command\Scan->execute()
#12 /var/www/nextcloud/core/Command/Base.php(169): Symfony\Component\Console\Command\Command->run()
#13 /var/www/nextcloud/3rdparty/symfony/console/Application.php(1012): OC\Core\Command\Base->run()
#14 /var/www/nextcloud/3rdparty/symfony/console/Application.php(272): Symfony\Component\Console\Application->doRunCommand()
#15 /var/www/nextcloud/3rdparty/symfony/console/Application.php(148): Symfony\Component\Console\Application->doRun()
#16 /var/www/nextcloud/lib/private/Console/Application.php(215): Symfony\Component\Console\Application->run()
#17 /var/www/nextcloud/console.php(100): OC\Console\Application->run()
#18 /var/www/nextcloud/occ(11): require_once('/var/www/nextcl...')
#19 {main}

[juliushaertl]

/backport to stable19

[juliushaertl]

/backport to stable18

[faily-bot]

🤖 beep boop beep 🤖

Here are the logs for the failed build:

Status of 32582: failure

mariadb10.1-php7.2

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) OCA\Files_Sharing\Tests\SharedMountTest::testPermissionMovedGroupShare with data set #222 ('folder', 29, 1)
Failed asserting that false is true.

/drone/src/apps/files_sharing/tests/SharedMountTest.php:367