You don't need it, KeePass2 has this feature already.
1. In your browser: Copy the URL of your .kdbx file from the Owncloud web interface (in Firefox: right click on filename, copy link address)
It should look like "https://example.com/owncloud/remote.php/webdav/datadir/datafile.kdbx"
2. In KeePass: File | Open | Open URL
paste URL, enter username and password
- (Owncloud 9.1, KeePass 2.34)