message: Fix magfield params in TFluka
diff: @@ -9,7 +9,7 @@ GEOEND
  *
  EVENTYPE 1.0
  BEAM 7000.0 MUON-
  -MGNFIELD 10.0
  +MGNFIELD 10.0 0.001
  SOURCE
  *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+
  USERDUMP 200. 37.0 -2.0 1.0 TRAKFILE
  