fix first formula,like #1164 (#1179)

apm-collector/apm-collector-analysis/analysis-worker-model/src/main/java/org/apache/skywalking/apm/collector/analysis/worker/model/impl/MergePersistenceWorker.java

@@ -86,6 +86,7 @@ public abstract class MergePersistenceWorker<INPUT_AND_OUTPUT extends StreamData
         if (mergeDataCache.containsKey(input.getId())) {
             mergeDataCache.get(input.getId()).mergeAndFormulaCalculateData(input);
         } else {
+            input.calculateFormula();
             mergeDataCache.put(input.getId(), input);
         }