Fixing test cases on daggyr for new polling

daggyd/libdaggyd/src/Server.cpp

@@ -180,7 +180,14 @@ namespace daggy::daggyd {
     if (!handleAuth(request))
       return;
 
-    auto dagSpec = dagFromJSON(request.body());
+    DAGSpec dagSpec;
+    try {
+      dagSpec = dagFromJSON(request.body());
+    }
+    catch (std::runtime_error &e) {
+      REQ_RESPONSE(Not_Acceptable, e.what());
+    }
+
     dagSpec.tasks =
         expandTaskSet(dagSpec.tasks, executor_, dagSpec.taskConfig.variables);