Warning message should show displayed property name

Description

Steps to reproduce:

1. User1 & User2 edit the same content version in 2 browsers.
2. User1 publishes it.
3. User2 edits a property, for example, Name in URL.

Expected:
Shows warning message "Could not save property..." with the displayed property name (in our example, Name in URL).

Actual:
Shows warning message with the property name defined in code (in our example, iroutable_routesegment).