Log Message:
Update to 15.0.4

Changelog:
15.0.4
Changes
    Make external storages browsable again in the web UI (server#14076)

15.0.3
Changes
    Upload new files in objectstore to a .part path first (server#13036)
    Broker: add timezone to CANCEL messages (server#13384)
    Add strengthify.min files (server#13546)
    Fix click app names (server#13575)
    Principals can be principal/user/ or principal/ from lega… (server#13582)
    Correctly handle displaynames returned from the sharee API (server#13585)
    Don't close input stream when writing in encrypted file (server#13588)
    Bump pear/archive_tar to 1.4.5 (server#13598)
    Fix integer background job id type error (server#13609)
    Fix user settings label translation (server#13611)
    Fix app navigation flickering on hover (server#13625)
    Update URL for federation (server#13636)
    Fix colorizeSvg with transformations that contain a comma (,) (server#13653)
    Use warning background color & primary text color for setting warnings \ 
(server#13665)
    Fix template paramter (server#13670)
    Cache tokens when using swift's v2 authentication (server#13740)
    Cleanup shared lock if changing to exclusive lock failed (server#13744)
    Honor remember_login_cookie_lifetime (server#13758)
    Fix integration of social sharing into the link popover menu (server#13761)
    Respect user locale in natural sort comparator (server#13762)
    Call proper function when fetching link shares in the breadcrumb view \ 
(server#13769)
    Add acceptance tests for moving and copying files (server#13771)
    Show proper default locale (server#13781)
    Ignore non existing users when retrieving details of group members (server#13792)
    Remove .css fileending from accessibility user css route (server#13793)
    Add icon to restore activity (server#13794)
    Fix long comment in dark theme (server#13804)
    Bump bower from 1.8.4 to 1.8.8 in /build (server#13821)
    Fix for high contrast theme (server#13852)
    Always use multipart uploader for s3 uploads (server#13882)
    Fix paged search with multiple bases (LDAP) (server#13884)
    Fix dropping a folder on a folder row (server#13887)
    Fix updating the password of a link share when passwords are enforced \ 
(server#13900)
    Add fallback for trashbin original location (server#13904)
    Allow shared versions again in legacy backend (server#13905)
    Improve data directory write checking for NFS mounts (server#13906)
    Clean pending 2FA authentication on password reset (server#13915)
    Forward error message from password policy (server#13918)
    Remove warning in case of external storage error (server#13920)
    Handle mail send error gracefully (server#13930)
    Bump pear/archive_tar from 1.4.3 to 1.4.5 (3rdparty#214)
    Move to SCSS and fix app icon for dark theme (activity#338)
    Fill screen in fullscreen mode for public videos. Fixes #77 \ 
(files_videoplayer#79)
    Use target="_blank" and rel="noreferrer noopener" \ 
(firstrunwizard#105)
    Fix notification documentation to reflect recent changes (notifications#258)