bug#14447: tramp-gvfs.el and xesam.el sometime fail to load

[Glenn Morris]

Package: emacs
Version: 24.3

I ssh'd into a remote machine where I had a graphical session running.
Now:

emacs -Q -nw -l xesam
emacs -Q -nw -l tramp-gvfs

both fail to load the associated library with error message:
  D-Bus error: "No connection to bus", :session

Debugger entered--Lisp error: (dbus-error "No connection to bus" :session)
  dbus-get-unique-name(:session)

It ought to always be possible to load lisp libraries.