Merge branch 'meson-prefix-usr' into 'master'

meson-installed polkit fails to run with default usr/lib prefix

See merge request !70

meson.build

@@ -4,6 +4,7 @@ project(
   license: 'LGPL2+',
   default_options: [
     'buildtype=debugoptimized',
+    'prefix=/usr',
     'cpp_std=c++17',
   ],
   meson_version: '>= 0.50.0',