Fix retrieval of corpus statistics for non-root instances

Change-Id: I7825c1ab0ca293eec0076b49595621c20fc173a3
diff --git a/dev/js/src/api.js b/dev/js/src/api.js
index 6942189..0b096f1 100644
--- a/dev/js/src/api.js
+++ b/dev/js/src/api.js
@@ -113,9 +113,8 @@
    * http://localhost:3000/corpus?cq=availability+%3D+%2FCC-BY.*%2F+%26+textClass+%3D+%22kultur%22
    */
   KorAP.API.getCorpStat = function (cq, cb){
-  	var url  =  "/corpus";
-  	url = url + "?cq=";
-  	url = url + cq;
+  	var url  =  KorAP.URL;
+    url += "/corpus?cq=" + cq;
   	KorAP.API.getJSON(url, cb);
   };