JAL-1923 fix: don’t add group twice

diff --git a/src/jalview/gui/TreeCanvas.java b/src/jalview/gui/TreeCanvas.java
index 9cb3d18..68573ef 100755 (executable)
--- a/src/jalview/gui/TreeCanvas.java
+++ b/src/jalview/gui/TreeCanvas.java
@@ -980,7 +980,6 @@ public class TreeCanvas extends JPanel implements MouseListener, Runnable,
       }
 
       // TODO can we push all of the below into AlignViewportI?
-      av.getAlignment().addGroup(sg);
       final AlignViewportI codingComplement = av.getCodingComplement();
       if (codingComplement != null)
       {