Fix compile on macOS due to lamba
Fix compile on macOS due to lamba

This should have been part of
    2020-03-04 Replace [=] with specific arguments
    c73a512ac1bb534274323fe0a31aac1bfaeee06f

Tarsnap/tarsnap-gui,Tarsnap/tarsnap-gui,Tarsnap/tarsnap-gui,Tarsnap/tarsnap-gui,Tarsnap/tarsnap-gui