FairRun: Remove fTask from Browsables

FairRunAna might add fTask to ROOT's "ListOfBrowsables".
FairRun deallocates it during its desctructor.
So let's remove it from the list there as well.

(cherry picked from commit f9f1648)

base/steer/FairRun.cxx

@@ -29,6 +29,7 @@
 #endif
 #include <TList.h>     // for TList
 #include <TObject.h>   // for TObject
+#include <TROOT.h>     // fot gROOT
 #include <cassert>     // for... well, assert
 
 TMCThreadLocal FairRun* FairRun::fRunInstance = 0;
@@ -85,7 +86,11 @@ FairRun::FairRun(Bool_t isMaster)
 FairRun::~FairRun()
 {
     LOG(debug) << "Enter Destructor of FairRun";
-    delete fTask;   // There is another tasklist in MCApplication,
+    if (fTask) {
+        // FairRunAna added it, but let's remove it here, because we own it
+        gROOT->GetListOfBrowsables()->Remove(fTask);
+        delete fTask;   // There is another tasklist in MCApplication,
+    }
     // but this should be independent
     delete fRtdb;   // who is responsible for the RuntimeDataBase
     delete fEvtHeader;