xfce4-terminal fails to open http url after right-click+"Open Link"

When I right-click on an http url in the terminal window (the url got underlined, i.e. recognised) and choose "Open Link" from the context menu, an empty Firefox window opens. Firefox is configured as my preferred webbrowser application.

This seems to have the same root cause as https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1429275, i.e. in Firefox 36.0 the "-remote" option was removed.

joerg@quad:/etc/thunderbird$ dpkg -l | grep firefox
ii firefox 36.0+build2-0ubuntu0.14.04.4 amd64 Safe and easy web browser from Mozilla
ii firefox-locale-en 36.0+build2-0ubuntu0.14.04.4 amd64 English language pack for Firefox

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: xfce4-terminal 0.6.3-1ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-46.77-generic 3.13.11-ckt15
Uname: Linux 3.13.0-46-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CurrentDesktop: XFCE
Date: Fri Mar 6 22:58:35 2015
InstallationDate: Installed on 2014-06-10 (269 days ago)
InstallationMedia: Xubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
SourcePackage: xfce4-terminal
UpgradeStatus: No upgrade log present (probably fresh install)