settings: Better error message if settings_type value is wrong

Author: slusarz

lib/data/settings.data.js

@@ -47,6 +47,9 @@ async function normalizeSettings(settings) {
 		}
 
 		for (const v2 of v.values) {
+			if (!v2) {
+				throw new Error("Incorrect value type for " + k)
+			}
 			v2.url = md.renderInline(v2.url)
 		}