dired: cannot operate on '.' or '..'

[fixermark]

Steps to reproduce:

1. Use s3ed-find-file to open a directory in dired
2. Select . or .. and hit RETURN to run dired-find-file.

Expected result: Does nothing (for .) or navigates up one level (for ..).

Observed result:

Error thrown. Backtrace:

Debugger entered--Lisp error: (error "Cannot operate on ‘.’ or ‘..’")
  signal(error ("Cannot operate on ‘.’ or ‘..’"))
  error("Cannot operate on `.' or `..'")
  dired-get-filename()
  s3ed-dired-find-s3-file(#f(compiled-function () (interactive nil) #<bytecode 0x1055441>))
  apply(s3ed-dired-find-s3-file #f(compiled-function () (interactive nil) #<bytecode 0x1055441>) nil)
  dired-find-file()
  funcall-interactively(dired-find-file)
  call-interactively(dired-find-file nil nil)
  command-execute(dired-find-file)