log a warning when the user supplied a label we could decode but was not in the proper format

salt/cloud/clouds/linode.py

@@ -1050,6 +1050,10 @@ def decode_linode_plan_label(label):
                     'Invalid Linode plan ({}) specified - call avail_sizes() for all available options'.format(new_label)
                 )
 
+            log.warning("An outdated Linode plan label was detected in your Cloud profile ({})."
+                        " Please update the profile to use"
+                        " the new label format {} for the requested Linode plan size.'.format(label, new_label))
+
             label = new_label
 
     return sizes[label]['PLANID']