Return error when client headers are missing (issue #19)

Return an error response when headers are missing instead of waiting indefinitely

ExpressAPI/src/middlewares/ClientVersionCheckerMiddleware.ts

@@ -27,7 +27,7 @@ class ClientVersionCheckerMiddleware {
 
                 new Session().sendResponse(res, HttpStatusCode.MethodNotAllowed, {}, `Unsupported client.`, DojoStatusCode.CLIENT_NOT_SUPPORTED);
             } else {
-                new Session().sendResponse(res, HttpStatusCode.MethodNotAllowed, {}, `Missing client headers.`, DojoStatusCode.CLIENT_HEADER_MISSING);
+                next();
             }
         };
     }