test-release.sh: Correct the logged configure command to match the one actually issued.

--disable-timestamps was added to the configure command way back in r142647 but
the command that echos this command to the log was not updated at the time.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223351 91177308-0d34-0410-b5e6-96231b3b80d8