Group list loader no longer works if group display name is just the extension

Up to v4.7.0, a list loader could just have just a display extension in the group query, and the loader would default to using the name parts for the parent folders. Now, there is a cryptic error "edu.internet2.middleware.grouper.exception.StemAddException: must contain a non-whitespace character". There is no detail on what group this failed on. If you run the loader query, there is no group with a blank name or display name, so it is not caused by any bad data. There is no way to know what the problem is, but it's due to a change in logic in the loader.

The only non-provisioning change in 4.7.0 was "GRP-4948: Provisioning on root folder doesn't propagate"

 
— a/grouper/src/grouper/edu/internet2/middleware/grouper/app/loader/GrouperLoaderType.java
+++ b/grouper/src/grouper/edu/internet2/middleware/grouper/app/loader/GrouperLoaderType.java
@@ -2144,7 +2144,7 @@ public enum GrouperLoaderType {
continue;
}

- String folderDisplayName = GrouperUtil.parentStemNameFromName(groupDisplayName);
+ String folderDisplayName = GrouperUtil.parentStemNameFromName(groupDisplayName, false);^M

if (folderNameToDisplayName.containsKey(folderName)) {