possible fix for #185: eliminated modification of existing list

I was not able to actually reproduce the issue in my testing
environment, so I cannot be actually sure that this fixes it, but it is
pretty much the only situation that could cause it, so...

de.gebit.integrity.remoting/src/de/gebit/integrity/remoting/entities/setlist/SetList.java

@@ -588,14 +588,17 @@ protected String calculateFullyQualifiedBaseName(SetListEntry anEntry) {
 	 */
 	public void setEntryInExecutionReference(Integer anEntryReference) {
 		entryInExecutionReference = anEntryReference;
-		pathOfEntriesInExecution.clear();
+		List<SetListEntry> tempNewPathOfEntriesInExecution = new ArrayList<SetListEntry>();
+
 		if (anEntryReference != null) {
 			SetListEntry tempCurrent = resolveReference(anEntryReference);
 			while (tempCurrent != null) {
-				pathOfEntriesInExecution.add(tempCurrent);
+				tempNewPathOfEntriesInExecution.add(tempCurrent);
 				tempCurrent = getParent(tempCurrent);
 			}
 		}
+
+		pathOfEntriesInExecution = tempNewPathOfEntriesInExecution;
 	}
 
 	public SetListEntry getEntryInExecution() {