[mCBM 2024] Fix for bug found after merging of !1872 with runs 3105-3107

See !1872 (comment 45195)

macro/beamtime/mcbm2024/mcbm_event_reco_L1.C

@@ -632,6 +632,9 @@ Bool_t mcbm_event_reco_L1(UInt_t uRunId                   = 3105,
     run->AddTask(globalFindTracks);
 
     if (bPV) {
+      CbmKF* KF = new CbmKF();
+      run->AddTask(KF);
+
       auto* pvFinder                   = new CbmPVFinderKFGlobal();
       CbmFindPrimaryVertex* findVertex = new CbmFindPrimaryVertex(pvFinder);
       findVertex->SetTrackType(ECbmDataType::kGlobalTrack);