Externals Updates, master branch (2019.11.07.)

Updated all projects to atlasexternals-2.0.45.

The full list of updates (atlasexternals@2.0.44...2.0.45) is:

• Introduced a fix for incremental builds of changes removing an __init__.py file from the project (ATLINFR-2417);
• Made Findtdaq.cmake and Findtdaq-common.cmake use the TDAQ_PLATFORM (cache) variable consistently (ATLINFR-2904);
• Tweaked the compilation settings to apply certain settings correctly when using Clang as the compiler (ATLINFR-2904);
• Fixed the Gdb build against Python 3 (ATLINFR-3221).