Look in old IOU images location in order to smooth transition

Fix #141

gns3server/modules/iou/iou_vm.py

@@ -146,6 +146,16 @@ class IOUVM(BaseVM):
             path = relative_path
 
         self._path = path
+
+        # In 1.2 users uploaded images to the images roots
+        # after the migration their images are inside images/IOU
+        # but old topologies use old path
+        if "IOU" not in self._path:
+            location, filename = os.path.split(self._path)
+            fix_path = os.path.join(location, "IOU", filename)
+            if os.path.isfile(fix_path):
+                self._path = fix_path
+
         if not os.path.isfile(self._path) or not os.path.exists(self._path):
             if os.path.islink(self._path):
                 raise IOUError("IOU image '{}' linked to '{}' is not accessible".format(self._path, os.path.realpath(self._path)))