Don't render a cross on place of worshop with denomination=jehovahs_witness

* This resolves #1058

Thanks to @donaciano for the initial version in #75.
Merge branch 'jehovah-witnesses' of https://github.com/math1985/openstreetmap-carto into math1985-jehovah-witnesses

Conflicts:
	project.mml
Merge branch 'math1985-jehovah-witnesses'