mintro: Fix introspecting installation paths
mintro: Fix introspecting installation paths

A new custom_install_mode element was added in 05c43cdcd

jeandet/meson,becm/meson,jpakkane/meson,pexip/meson,QuLogic/meson,QuLogic/meson,jeandet/meson,becm/meson,jpakkane/meson,QuLogic/meson,MathieuDuponchelle/meson,pexip/meson,jpakkane/meson,becm/meson,jpakkane/meson,pexip/meson,becm/meson,jpakkane/meson,jeandet/meson,thiblahute/meson,QuLogic/meson,pexip/meson,MathieuDuponchelle/meson,becm/meson,MathieuDuponchelle/meson,becm/meson,becm/meson,mesonbuild/meson,pexip/meson,mesonbuild/meson,becm/meson,thiblahute/meson,mesonbuild/meson,thiblahute/meson,QuLogic/meson,QuLogic/meson,pexip/meson,becm/meson,mesonbuild/meson,jeandet/meson,MathieuDuponchelle/meson,thiblahute/meson,QuLogic/meson,mesonbuild/meson,jpakkane/meson,jpakkane/meson,jeandet/meson,MathieuDuponchelle/meson,jeandet/meson,mesonbuild/meson,MathieuDuponchelle/meson,MathieuDuponchelle/meson,becm/meson,thiblahute/meson,mesonbuild/meson,thiblahute/meson,jpakkane/meson,thiblahute/meson,pexip/meson,mesonbuild/meson,jpakkane/meson,MathieuDuponchelle/meson,mesonbuild/meson,pexip/meson,pexip/meson,MathieuDuponchelle/meson,pexip/meson,jeandet/meson,QuLogic/meson,mesonbuild/meson,QuLogic/meson,jeandet/meson,jeandet/meson,thiblahute/meson,thiblahute/meson