add conaction Handling

public/js/connectToAPI.js

 var coordinatesBB = []
 //var url = "https://simstadt-api.iaf-ex.hft-stuttgart.de:8080/workflow/execute" //old link
-var url = "http://vm24.fkc.hft-stuttgart.de:8082/workflow/execute" // URL to API
-var url2 = "http://vm24.fkc.hft-stuttgart.de:8082/workflow/timedShadowValueByDay/"
+var url = "http://vm24.fkc.hft-stuttgart.de:8080/workflow/execute" // URL to API
+var url2 = "http://vm24.fkc.hft-stuttgart.de:8083/workflow/timedShadowValueByDay/"
 /*TODO#1:   -get current data from the api and create local test data (apiData foler)
             -add connection handeling  (error messages when there isnt a connection and then using the local test data)
 */
@@ -38,6 +38,10 @@ async function fetchshadowDataJSON() {
             "Content-Type": "application/json",
             "Authorization": "Basic YWRtaW46YWRtaW4xMjM="
         }
+    }).then(function() {
+        console.log("ok");
+    }).catch(function() {
+        alert("Connetion error to server, use local data")
     })
     const data = await response.json()
     return data