Update the ref to vtkDICOM remote module

Fix vtkDICOMReader tilted-gantry PatientMatrix for BottomUp.
This is required in order for vtkDICOMCTRectifer to work when
the reader uses "BottomUp" row order (which is the default).

Remote/vtkDICOM.remote.cmake

@@ -5,6 +5,6 @@
 vtk_fetch_module(vtkDICOM
   "Dicom classes and utilities"
   GIT_REPOSITORY https://github.com/dgobbi/vtk-dicom
-  # vtk-dicom release 0.8.12 plus warning and build fixes
-  GIT_TAG 73e1420340945bb476c9049aead3067ebe1eee1a
+  # vtk-dicom release 0.8.12 plus bug fixes
+  GIT_TAG 324057367c4c1390ed51f0a9bc2000c254d4e811
   )