Ticket #3131: incorrect tilde expandion in copy/rename/move dialog.

Revert "(file_mask_dialog): don't call tilde_expand() because
vfs_path_from_str() returns an absolute path."

This reverts commit 1b774ac1fe89501c314d885ce41e2266d1faa295.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '3131_copy_move_tilde_expand'

* 3131_copy_move_tilde_expand:
  Ticket #3131: incorrect tilde expandion in copy/rename/move dialog.