vcs: Fixed change lists grouping in "Repository" tab for custom change list columns - use real change list column value for grouping instead of just "CommittedChangeList.getBranch()" value (that was used by mistake)

platform/vcs-impl/src/com/intellij/openapi/vcs/changes/committed/SelectGroupingAction.java

@@ -135,7 +135,9 @@ public class SelectGroupingAction extends LabeledComboBoxAction {
 
     @Override
     public String getGroupName(@NotNull CommittedChangeList changeList) {
-      return changeList.getBranch();
+      Object value = myColumn.getValue(changeList);
+
+      return value != null ? value.toString() : null;
     }
 
     @Override