AtlasExternals updates for CC7 Compatibility for 21.9
Updated all projects to atlasexternals-1.0.48.5. The list of changes wrt. atlasexternals-1.0.48.2 (which Athena was using, but every other project was still using atlasexternals-1.0.48...) is the following (atlasexternals@1.0.48.2...1.0.48.4). See also !36624 (merged) and !36899 (merged).
This update should at least allow the compilation of Athena proper to start for the x86_64-centos7-gcc62-opt
platform. No changes in output for the x86_64-slc6-gcc62-opt
nightly platform are expected.
FYI @akraszna