In Lubuntu 19.04, a file does not open on double-click when vim is configured as default application for this filetype

# Steps to reproduce

After a fresh Lubuntu 19.04 installation in a virtual machine:
- create an empty file on the desktop,
- right-click on the file>Properties>General>Open With: Vim>OK,
- double click on the file.

# Expected results

Double-clicking on the file should open it in vim (terminal).

# Actual results

Nothing happens on double-click.

# Affected version

Lubuntu 19.04
pcmanfm-qt 0.14.1

# Additional notes

Note 1: if we select gVim or FeatherPad instead of vim as the default application to open the file, it opens.

Note 2: When the default application to open the file is set to vim, if instead of double-clicking on the file we right-click>Open With...>Vim, then it opens. So it looks like it is only when we double-click on the file that nothing happen.

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: pcmanfm-qt 0.14.1-0ubuntu1
ProcVersionSignature: Ubuntu 5.0.0-13.14-generic 5.0.6
Uname: Linux 5.0.0-13-generic x86_64
ApportVersion: 2.20.10-0ubuntu27
Architecture: amd64
CurrentDesktop: LXQt
Date: Thu May 2 21:52:52 2019
InstallationDate: Installed on 2019-05-02 (0 days ago)
InstallationMedia: Lubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
SourcePackage: pcmanfm-qt
UpgradeStatus: No upgrade log present (probably fresh install)