Added SAL_USE_VCLPLUGIN=qt5 env var in session.conf so libreoffice use qt5 VCL

Summary:
Added SAL_USE_VCLPLUGIN=qt5 enviroment variable in session.conf xdg so libreoffice use qt5 vcl plugin

See T146 for context.

Test Plan: run env in terminal and se the value of SAL_USE_VCLPLUGIN

Reviewers: wxl, tsimonq2, kc2bez

Reviewed By: wxl, kc2bez

Subscribers: wxl

Differential Revision: https://phab.lubuntu.me/D72

debian/changelog

@@ -1,3 +1,9 @@
+lubuntu-default-settings (20.04.2) focal; urgency=medium
+
+  * Added SAL_USE_VCLPLUGIN=qt5 env variable in session.conf.
+
+ -- Hans P Möller <hmollercl@lubuntu.me>  Sat, 25 Jan 2020 22:44:42 -0300
+
 lubuntu-default-settings (20.04.1) focal; urgency=medium
 
   * Added default theme for XscreenSaver

src/etc/xdg/xdg-Lubuntu/lxqt/session.conf

@@ -7,6 +7,7 @@ BROWSER=firefox
 GTK_CSD=0
 GTK_OVERLAY_SCROLLING=0
 TERM=qterminal
+SAL_USE_VCLPLUGIN=qt5
 
 [Mouse]
 cursor_size=18