Add CAF_ASSERT to RigCaseCellResultsData::statistics

* Currently the code crashes in a dual porosity case.
* This commit doesn't fix the problem but adds an assert which triggers instead of just crashing

ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.cpp

@@ -2808,7 +2808,9 @@ void RigCaseCellResultsData::assignValuesToTemporaryLgrs(const QString&       re
 //--------------------------------------------------------------------------------------------------
 RigStatisticsDataCache* RigCaseCellResultsData::statistics(const RigEclipseResultAddress& resVarAddr)
 {
-    return m_statisticsDataCache[findScalarResultIndexFromAddress(resVarAddr)].p();
+    size_t scalarResultIndex = findScalarResultIndexFromAddress(resVarAddr);
+    CAF_ASSERT(scalarResultIndex < m_statisticsDataCache.size());
+    return m_statisticsDataCache[scalarResultIndex].p();
 }