[BUG] fail to open the configuration pannel for a VM without eths

[Francesco Apollonio]

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/virtualbricks/gui/gui.py", line 211, in brick_to_cell
    48)
glib.GError: Apertura del file «/tmp/qemuicon_ubuntu_grey.png» non riuscita: File o directory non esistente
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/virtualbricks/gui/gui.py", line 2530, in on_brick_configure
    self.curtain_up()
  File "/usr/local/lib/python2.7/dist-packages/virtualbricks/gui/gui.py", line 960, in curtain_up
    self.config_brick_prepare()
  File "/usr/local/lib/python2.7/dist-packages/virtualbricks/gui/gui.py", line 601, in config_brick_prepare
    self.update_vmplugs_tree()
  File "/usr/local/lib/python2.7/dist-packages/virtualbricks/gui/gui.py", line 2749, in update_vmplugs_tree
    self.treeview_order('treeview_networkcards', self.vmplugs, 0)
  File "/usr/local/lib/python2.7/dist-packages/virtualbricks/gui/gui.py", line 356, in treeview_order
    moved = self._treeorder_continue(tree, model, itr, field, ascending)
  File "/usr/local/lib/python2.7/dist-packages/virtualbricks/gui/gui.py", line 335, in _treeorder_continue
    nxt = model.iter_next(itr)
TypeError: iter should be a GtkTreeIter

[Francesco Apollonio (lorddex)]

fixed in r324