Hello, A few months back I authored a patch for caja-dropbox for this same removal. Please see 866026 for a potential solution, though it likely won't work out-of-the-box for nautilus-dropbox, it should save whoever takes up the torch some significant time and trouble.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=866026 Cheers, Paul Bransford
