BUG: Incorrect CDash URL in CTestConfig.cmake.

CDash has moved from www.cdash.org/CDash to open.cdash.org/.

Change-Id: I0b751eda4fa6945104cc0a1d5443a213b0a91755
Merge topic 'cdash-site'

bd33645 BUG: Incorrect CDash URL in CTestConfig.cmake.