Tests: Fix obscure RunCMake.CTestSubmit 'drop' case failures

When curl is given a URL of the form '<something>://' it tries to
resolve '<something>' as a host name.  If the host happens to exist and
have a server then the drop might actually appear to work.  Instead use
an explicit '-no-site-' host to ensure it cannot connect.

Reported-by: Gilles Khouzam <Gilles.Khouzam@microsoft.com>

Tests/RunCMake/CTestSubmit/CTestConfig.cmake.in

@@ -3,3 +3,4 @@ set(CTEST_PROJECT_NAME "CTestSubmit@CASE_NAME@")
 # Intentionally leave out other upload-related CTestConfig.cmake settings
 # so that any ctest_submit calls fail with an error message.
 set(CTEST_DROP_METHOD "@CASE_DROP_METHOD@")
+set(CTEST_DROP_SITE "@CASE_DROP_SITE@")

Tests/RunCMake/CTestSubmit/RunCMakeTest.cmake

@@ -2,6 +2,7 @@ include(RunCMake)
 
 # Default case parameters.
 set(CASE_DROP_METHOD "http")
+set(CASE_DROP_SITE "-no-site-")
 set(CASE_CTEST_SUBMIT_ARGS "")
 
 function(run_ctest CASE_NAME)