vtk_common: Changed the CDash submission url for VTK

This was moved quite some time ago, go directly to the current URL.

vtk_common.cmake

@@ -366,8 +366,8 @@ endif()
   # CTestConfig.cmake info here.
   set(CTEST_NIGHTLY_START_TIME "01:00:00 UTC")
   set(CTEST_DROP_METHOD "http")
-  set(CTEST_DROP_SITE "www.cdash.org")
-  set(CTEST_DROP_LOCATION "/CDash/submit.php?project=VTK")
+  set(CTEST_DROP_SITE "open.cdash.org")
+  set(CTEST_DROP_LOCATION "/submit.php?project=VTK")
   set(CTEST_DROP_SITE_CDASH TRUE)
 endif()