[O] M-RET is not working in the ogr-plus-contrib-20170918

[Ярослав Данько]

Hi, all. After installing the latest ogr-plus-contrib 20170918 i noticed
that M-RET is not working anymore to continue the list or to insert a new
heading. If this is a intended change, what combination of keys is now
instead of the old one? Thanks in advance.