Work with both FUSE 2 and FUSE 3
    
    There is a general desire to migrate away from FUSE 2 to FUSE 3:
    https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/UUOKLRLQHN2AC4SLAXERC7QAKW6FBSFX/
    
    flatpak-builder requires FUSE indirectly through it's use of OSTree's
    rofiles-fuse binary.  Until now, flatpak-builder could only work with
    a rofiles-fuse binary that was built against FUSE 2 because of the
    use of some optimization options that are only needed for FUSE 2 and
    hence don't work with FUSE 3.  See:
    https://github.com/flatpak/flatpak-builder/commit/99b35552274150bd
    
    This disables the optimization in the hope that OSTree will switch to
    building against FUSE 3.  In the meantime, flatpak-builder will be
    slower but will continue to work with FUSE 2.