prevent change to navbar url in pdf viewer

return false from pdf <a> click handler

services/web/public/coffee/ide/pdfng/directives/pdfAnnotations.coffee

@@ -41,4 +41,5 @@ define [
 					element.href = "#" + link.dest;
 					element.onclick = (e) =>
 						@navigateFn link
+						return false
 	]