Uninstalling user_ldap using market app leads to a broken server.

Steps to reproduce

0. Having a server with market app installed and enabled.
1. Using admin user go to market.
2. Search for user_ldap app.
3. Install it.
4. Uninstall it.
5. Access the server.

Expected behaviour

App user_ldap unsintalled. Server working correctly.

Actual behaviour

500 errors. Server failing in ldap code.

Server configuration

Operating system:
Ubuntu 16.04

Web server:
Apache

Database:
MySQL

PHP version:
7.0

ownCloud version: (see ownCloud admin page)
current master
{"installed":"true","maintenance":"false","needsDbUpgrade":"false","version":"10.0.2.1","versionstring":"10.0.2.1","edition":"Enterprise","productname":"ownCloud"}

Updated from an older ownCloud or fresh install:
Fresh

The content of config/config.php:

Are you using external storage, if yes which one: local/smb/sftp/...
No.

Are you using encryption:
No

Logs
When accessing the server

{"reqId":"puq1JvZi5uE02eMRDztN","level":3,"time":"2017-07-17T12:48:20+00:00","remoteAddr":"HIDDEN_IP","user":"admin","app":"index","method":"GET","url":"\/index.php\/logout?requesttoken=BxYfPTEFK1VzWhQOQCxKDwMQPEZxEhZSBTJ3EhkmbDo%3D%3A1wgrhsXmD2Szsu89isH5EJp4dbCwpn4XnW1v5OPlps8%3D","message":"Exception: {\"Exception\":\"Error\",\"Message\":\"Class 'OCA\\\\User_LDAP\\\\Helper' not found\",\"Code\":0,\"Trace\":\"#0 \\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php(42): OCA\\\\Files_LDAP_Home\\\\Storage::initiateLDAPAccess(Object(OC\\\\AllConfig))\\n#1 \\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php(150): OCA\\\\Files_LDAP_Home\\\\Storage->__construct(Array)\\n#2 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/legacy\\\/hook.php(105): OCA\\\\Files_LDAP_Home\\\\Storage::setup(Array)\\n#3 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Filesystem.php(452): OC_Hook::emit('OC_Filesystem', 'post_initMountP...', Array)\\n#4 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Filesystem.php(375): OC\\\\Files\\\\Filesystem::initMountPoints('admin')\\n#5 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/legacy\\\/util.php(297): OC\\\\Files\\\\Filesystem::init('admin', '\\\/admin\\\/files')\\n#6 \\\/opt\\\/owncloud\\\/lib\\\/base.php(919): OC_Util::setupFS()\\n#7 \\\/opt\\\/owncloud\\\/index.php(49): OC::handleRequest()\\n#8 {main}\",\"File\":\"\\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php\",\"Line\":97}"}
{"reqId":"6P9H3rs7QWLCmDs1OsoS","level":3,"time":"2017-07-17T12:48:20+00:00","remoteAddr":"HIDDEN_IP","user":"admin","app":"index","method":"GET","url":"\/index.php\/undefined\/img\/notifications.svg","message":"Exception: {\"Exception\":\"Error\",\"Message\":\"Class 'OCA\\\\User_LDAP\\\\Helper' not found\",\"Code\":0,\"Trace\":\"#0 \\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php(42): OCA\\\\Files_LDAP_Home\\\\Storage::initiateLDAPAccess(Object(OC\\\\AllConfig))\\n#1 \\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php(150): OCA\\\\Files_LDAP_Home\\\\Storage->__construct(Array)\\n#2 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/legacy\\\/hook.php(105): OCA\\\\Files_LDAP_Home\\\\Storage::setup(Array)\\n#3 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Filesystem.php(452): OC_Hook::emit('OC_Filesystem', 'post_initMountP...', Array)\\n#4 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Filesystem.php(375): OC\\\\Files\\\\Filesystem::initMountPoints('admin')\\n#5 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/legacy\\\/util.php(297): OC\\\\Files\\\\Filesystem::init('admin', '\\\/admin\\\/files')\\n#6 \\\/opt\\\/owncloud\\\/lib\\\/base.php(919): OC_Util::setupFS()\\n#7 \\\/opt\\\/owncloud\\\/index.php(49): OC::handleRequest()\\n#8 {main}\",\"File\":\"\\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php\",\"Line\":97}"}
{"reqId":"4ieWGJZEW4dTVUw3v4Ze","level":3,"time":"2017-07-17T12:48:27+00:00","remoteAddr":"HIDDEN_IP","user":"admin","app":"index","method":"GET","url":"\/","message":"Exception: {\"Exception\":\"Error\",\"Message\":\"Class 'OCA\\\\User_LDAP\\\\Helper' not found\",\"Code\":0,\"Trace\":\"#0 \\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php(42): OCA\\\\Files_LDAP_Home\\\\Storage::initiateLDAPAccess(Object(OC\\\\AllConfig))\\n#1 \\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php(150): OCA\\\\Files_LDAP_Home\\\\Storage->__construct(Array)\\n#2 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/legacy\\\/hook.php(105): OCA\\\\Files_LDAP_Home\\\\Storage::setup(Array)\\n#3 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Filesystem.php(452): OC_Hook::emit('OC_Filesystem', 'post_initMountP...', Array)\\n#4 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Filesystem.php(375): OC\\\\Files\\\\Filesystem::initMountPoints('admin')\\n#5 \\\/opt\\\/owncloud\\\/lib\\\/private\\\/legacy\\\/util.php(297): OC\\\\Files\\\\Filesystem::init('admin', '\\\/admin\\\/files')\\n#6 \\\/opt\\\/owncloud\\\/lib\\\/base.php(919): OC_Util::setupFS()\\n#7 \\\/opt\\\/owncloud\\\/index.php(49): OC::handleRequest()\\n#8 {main}\",\"File\":\"\\\/opt\\\/owncloud\\\/apps\\\/files_ldap_home\\\/lib\\\/Storage.php\",\"Line\":97}"}

Client configuration

Browser
Edge

Start with apps/files_ldap_home/lib/Storage.php, especially initiateLDAPAccess and line 97, then reproduce the install/uninstall sequence for user_ldap. Confirm how the missing OCA\User_LDAP\Helper class is reached after uninstall. Done means the server no longer returns 500 errors after user_ldap is removed.