OPEN - task #245: Fix the default interpolation configuration for

The next bug fix for review (on the hotfix branch) once the current hotfixes are approved and added to 3.2.x

scatter plot 
http://github.com/ControlSystemStudio/cs-studio/issues/issue/245

Change-Id: I7076f5c8af91a223a32fbf0d7761010acab2261d