Fixes the following error:
```
qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""
This application failed to start because no Qt platform plugin could be initialized.
Reinstalling the application may fix this problem.
```
See also #54484 and others.
* treewide: http -> https sources
This updates the source urls of all top-level packages from http to
https where possible.
* buildtorrent: fix url and tab -> spaces
This reverts commit 83406bc171, because
it broke the build.
x2goclient requires to be built with its top-level (hand coded) Makefile
(in accordance with upstream documentation). Invoking qmake directly on
the .pro file, without specifying a separate build tree, will overwrite
the Makefile and break the build.
For instance, there are no install rules in the .pro file. That exists
only in the Makefile.
This will probably be mandatory soon, and is a step in the right
direction. Removes the deprecated meta.version, and move some meta
sections to the end of the file where I should have put them in
the first place.
