CategoryOverpassFilter: before rendering filters, set global.currentCategory

src/CategoryOverpassFilter.js

@@ -25,6 +25,7 @@ class CategoryOverpassFilter {
     for (var k in this.data) {
       let f = this.data[k]
       if ('name' in f && typeof f.name === 'string') {
+        global.currentCategory = this.master
         let t = OverpassLayer.twig.twig({ data: f.name, autoescape: true })
         f.name = t.render({}).toString()
       } else if (!('name' in f)) {