Blueman does not respect XDG_DOWNLOAD_DIR variable from .config/user-dirs.dirs

[Norbert]

Steps to reproduce:
1. Install Ubuntu MATE 16.04 LTS or Ubuntu 18.04 LTS
2. Change name of the Downloads dir in *~/.config/user-dirs.dirs* file (as in https://askubuntu.com/a/243567/66509 )
3. Reboot
4. Login

Expected results:
  BlueMan respects the settings in *~/.config/user-dirs.dirs* and know about new Downloads path.

Actual results:
  BlueMan shows error GUI and asks user about missed Download directory -
  "Configured directory for incoming files does not exist

   Please make sure that directory "/home/user/Downloads" exists or configure it with blueman-services"

  also it has old value in `dconf`:

  $ dconf dump / | grep -A2 blueman*.transfer
  [org/blueman/transfer]
  shared-path='/home/xenial/Downloads'

Possible workaround:
  change directory by hand in `blueman-services` GUI.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: blueman 2.0.4-1ubuntu2
ProcVersionSignature: Ubuntu 4.4.0-128.154-generic 4.4.131
Uname: Linux 4.4.0-128-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
CurrentDesktop: MATE
Date: Sun Jun 24 22:04:13 2018
InstallationDate: Installed on 2018-01-04 (171 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
SourcePackage: blueman
UpgradeStatus: No upgrade log present (probably fresh install)

[Eugene Nesudimov (oigenn)]

Workaround is change directory by hand in dconf Editor (in org - blueman - trasfer, then double click on path)