Menu items not populated on node edit if there's another HS field on the form

Tested this with multiple content types, if I have a taxonomy term reference field on a node which is using HS my menu items no longer get populated. I've got other sites using other versions of this module and it works just fine on them so I pulled one of their version over and looked at the diffs and this line seems to fix it.

This came from another issue #1304002: [explode() expects parameter 2 to be string, array given in menu_node_submit()] warning msg where the patch was never committed because the "duplicate" issue #1272538: Hierarchical Select Menu should also flatten on submit of node forms's patch was committed instead.