fix for NullPointerException on overview map

[RinkeHeida]

I have a solution for this error when using an overviewMap:
java.lang.NullPointerException: null
at org.mapfish.print.map.MapChunkDrawer.renderImpl(MapChunkDrawer.java:86

I seem not be able to push my commit to this repo, can you add me as contributor?

Or use this fix in the next release:

src\main\java\org\mapfish\print\map\MapChunkDrawer.java

        mainTransformer = context.getLayout().getMainPage().getMap(name).createTransformer(context, params);

->

        mainTransformer = context.getLayout().getMainPage().getMap(null).createTransformer(context, params);

[jodygarnett]

Can you add that as a PR? You can do so right from GitHub by clicking edit on the file...

This project is not actively maintained so you really have to do stuff yourself there is nobody listening to do work for ya

[RinkeHeida]

Direct edit is not possible as I am not an owner.
When I edit through github.dev it is not possible to commit before I can do a PR