исправила баг на delete undo/redo

git-svn-id: svn://192.168.3.15/activex/AVS/Sources/TeamlabOffice/trunk/OfficeWeb@49003 954022d7-b5bf-4e40-9824-e11837661b57

Word/Math/mathContent.js

@@ -3775,8 +3775,10 @@ CMathComposition.prototype =
 
             if(start !== end)
                 Pos = start < end ? start: end;
-            else
+            else if(order == 1)
                 Pos = this.SelectContent.CurPos;
+            else
+                Pos = this.SelectContent.CurPos + 1;
         }
 
         this.ClearSelect();