Was using wrong error message.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@271530 13f79535-47bb-0310-9956-ffa450edef68

proposal/myrmidon/src/java/org/apache/myrmidon/components/configurer/DefaultConfigurer.java

@@ -359,7 +359,7 @@ public class DefaultConfigurer
         }
         catch( final ContextException e )
         {
-            final String message = REZ.getString( "get-ref.error", id );
+            final String message = REZ.getString( "unknown-reference.error", id );
             throw new ConfigurationException( message, e );
         }