ifupdown2 must handle JSON input that is non-list

Ticket: CM-4417
Reviewed By: roopa
Testing Done: Build powerpc image and tested alternate json format

ifupdown2 was patched to handle nonlist JSON input since this
is a valid format.
(cherry picked from commit 2597194f6f34344495f3a2b44bfe1d05887e1e77)

ifupdown/networkinterfaces.py

@@ -410,6 +410,11 @@ class networkInterfaces():
             fp = open(filename)
             ifacedicts = json.load(fp)
                             #object_hook=ifaceJsonDecoder.json_object_hook)
+
+        # we need to handle both lists and non lists formats (e.g. {{}})
+        if not isinstance(ifacedicts,list):
+            ifacedicts = [ifacedicts]
+
         for ifacedict in ifacedicts:
             ifaceobj = ifaceJsonDecoder.json_to_ifaceobj(ifacedict)
             if ifaceobj: