Tests: Fix RunCMake.CPack_RPM.DEBUGINFO test case

Since commit c826745f5a (CPack/DEB: Do not crash when asked for debug
symbols when there are none, 2020-10-29, v3.20.0-rc1~461^2) the test
fails because CPackRPM warns about no sources in which to find debug
symbols.  Add expected output for this case.
1 file changed