quick fix for the currently quite dirty error detection for non-map types (#3)

Author: dfangl

cmd/localstack/custom_interop.go

@@ -117,12 +117,11 @@ func NewCustomInteropServer(lsOpts *LsOpts, delegate rapidcore.InteropServer, lo
 				var errR map[string]any
 				marshalErr := json.Unmarshal(invokeResp.Body, &errR)
 
-				if marshalErr != nil {
-					log.Fatalln(marshalErr)
+				isErr := false
+				if marshalErr == nil {
+					_, isErr = errR["errorType"]
 				}
 
-				_, isErr := errR["errorType"]
-
 				if isErr {
 					log.Infoln("Sending to /error")
 					_, err = http.Post(server.upstreamEndpoint+"/invocations/"+invokeR.InvokeId+"/error", "application/json", bytes.NewReader(invokeResp.Body))