torbrowser initial setup fails because of wrong signature

[Etienne Papegnies]

When launching Tor Browser after initial install on Ubuntu MATE 16.04.3, the program is downloaded but signature verification fails. (See attached screenshot)

$ torbrowser-launcher
Tor Browser Launcher
By Micah Lee, licensed under MIT
version 0.2.4
https://github.com/micahflee/torbrowser-launcher
Downloading and installing Tor Browser for the first time.
Downloading https://dist.torproject.org/torbrowser/update_2/release/Linux_x86_64-gcc3/x/en-US
Latest version: 7.0.3
Downloading https://www.torproject.org/dist/torbrowser/7.0.3/tor-browser-linux64-7.0.3_fr.tar.xz.asc
Downloading https://www.torproject.org/dist/torbrowser/7.0.3/tor-browser-linux64-7.0.3_fr.tar.xz
Verifying signature

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: torbrowser-launcher 0.2.4-1
ProcVersionSignature: Ubuntu 4.10.0-28.32~16.04.2-generic 4.10.17
Uname: Linux 4.10.0-28-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CurrentDesktop: MATE
Date: Thu Aug 3 16:52:15 2017
InstallationDate: Installed on 2017-08-03 (0 days ago)
InstallationMedia: Ubuntu-MATE 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
SourcePackage: torbrowser-launcher
UpgradeStatus: No upgrade log present (probably fresh install)