geant4-toolfile: add -ftls-model=initial-exec -pthread to CXXFLAGS

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
geant4: bump version to 10.0.cand00a

The following version decrease TLS segment size on libG4processes.so
object. Originally 0x00000000002ed220 (2996.53125 kilobytes) now
only 0x00000000000662c0 (408.6875 kilobytes).

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>