COMP: Specify "patched" git branch in DCMTK external project

CMakeExternals/DCMTK.cmake

@@ -21,6 +21,7 @@ IF(${add_project})
 
     ExternalProject_Add(${proj}
         GIT_REPOSITORY "${git_protocol}://github.com/commontk/DCMTK.git"
+        GIT_TAG "patched"
         CMAKE_GENERATOR ${gen}
         BUILD_COMMAND ""
         CMAKE_ARGS