Fix misc. build warnings with gcc/clang in nightlies
Aim in LHCb nightlies testing must eventually be for Allen to build 'green' for all supported platforms. Currently there are a number of warnings with gcc/clang, as seen at e.g.
This MR addresses these warnings.
There are two remaining (the first two in the links above), from the configuration step, which will eventually also need to be suppressed
CMake Warning at Gaudi/InstallArea/x86_64-centos7-gcc9-opt/cmake/GaudiBuildFlags.cmake:45 (message):
375
CMAKE_BUILD_TYPE set to RelWithDebInfo, but BINARY_TAG build type opt
376
implies Release
and
CMake Warning at cmake/GenerateConfiguration.cmake:95 (message):
436
Failed to generate sequence. Please note Python 3 AND (CVMFS (sft.cern.ch)
437
OR clang >= 9.0.0) are required to be able to generate configurations.