This is added specifically for the QPA platform and theme plugins, to
honor the QT_QPA_PLATFORM_PLUGIN_PATH environment variable and the
(inadvisable) -platformpluginpath command-line argument.
This removes the last QFactoryLoader used with an empty path (also the
only two that could be reached), which were causing a scan of the
application's binary directory whenever the platform plugin path was
set. In case of applications installed to /usr/bin, the entire /usr/bin
was scanned, which can be qualified as "not good".
Fixes: QTBUG-97950
Pick-to: 6.3
Change-Id: Ice04365c72984d07a64dfffd16b47fe1d22f26d3
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
ddba24535f