Launch applications (executable files) by double-clicking

3a22ed5b removes the ability to launch applications (executable files) by double-clicking them in Nautilus or on the desktop, as was reported at https://www.omgubuntu.co.uk/2018/05/nautilus-remove-ability-launch-binaries-apps.

Please preserve/restore this capability, as launching applications has been one of they key features of file managers (see https://medium.com/@probonopd/make-it-simple-linux-desktop-usability-part-6-1c03de7c00a9 for some historic examples).