Restore ATOM_SERVER_HOST default for ADIOS

set(ATL_ARCHIVE_COMPONENT adios2_atl-development)

set(ATL_HEADER_COMPONENT adios2_atl-development)

# Override ATL's default atom server to avoid blocking TCP connect to an

# external HTTP endpoint.  Compute nodes on machines like Frontier have no

# route to the internet, causing SST to hang indefinitely during SstWriterOpen

# / SstReaderOpen.  The old UDP-based default fails fast when unreachable.

set(ATOM_SERVER_HOST "atomhost.cercs.gatech.edu")

add_subdirectory(atl)

set(atl_DIR ${CMAKE_CURRENT_BINARY_DIR}/atl CACHE INTERNAL "")

setup_libversion_dir(atl)