Obs changed to ref, because it caused bugs in post-processing

Q1Q1 correlations can be in resolution formulaes, and result of dividing any data container on container with even one obs weight is not drawable

src/correlate/CorrelationTask.cpp

@@ -93,7 +93,7 @@ void CorrelationTask::AddQ1Q1Correlations(const Qn::QvectorConfig& a, const Qn::
       name,
       cor.second,
       {a_name, b_name},
-      {obs, ref},
+      {ref, ref},
       Qn::EventAxes(event_),
       config_->GetNSamples()))
       .BookMe(dfs_);