Fix lookup of labelprop in REST

The label property by default is the alphabetically first one which
turns out to be 'activity' in most cases, this is a protected property.
So we need to also search protected properties when determining
labelprop.

Author: schlatterbeck

roundup/rest.py

@@ -754,7 +754,8 @@ def get_collection(self, class_name, input):
         # add verbose elements. 2 and above get identifying label.
         if verbose > 1:
             lp = class_obj.labelprop()
-            display_props[lp] = class_obj.properties[lp]
+            # Label prop may be a protected property like activity
+            display_props[lp] = class_obj.getprops (protected = True)[lp]
 
         # extract result from data
         result={}