Forward messages with empty payloads (QC-401) (#474)

Author: Barthelemy

Framework/src/TaskRunner.cxx

@@ -159,7 +159,7 @@ CompletionPolicy::CompletionOp TaskRunner::completionPolicyCallback(o2::framewor
   CompletionPolicy::CompletionOp action = CompletionPolicy::CompletionOp::Wait;
 
   for (auto& input : inputs) {
-    if (input.header == nullptr || input.payload == nullptr) {
+    if (input.header == nullptr) {
       continue;
     }
 
@@ -263,7 +263,7 @@ std::tuple<bool /*data ready*/, bool /*timer ready*/> TaskRunner::validateInputs
   bool timerReady = false;
 
   for (auto& input : inputs) {
-    if (input.header != nullptr && input.payload != nullptr) {
+    if (input.header != nullptr) {
 
       const auto* dataHeader = get<DataHeader*>(input.header);
       assert(dataHeader);