M #-: onedb change-live --append with multiindex

do not update the matching elements on append

(cherry picked from commit d266248)

src/onedb/onedb_live.rb

@@ -451,7 +451,9 @@ def change_body(object, xpath, value, options = {})
                 if options[:delete]
                     el.remove
                 else
-                    el.content = value
+                    if !options[:append]
+                        el.content = value
+                    end
                 end
             end