Fix some gcc8 warnings

Fix some gcc8 warnings:

GaudiHive:

• catch polymorphic exceptions by reference

GaudiProfiling:

• Avoid using sprintf with the same source and destination buffers
• Replace strncpy with memcpy
• Use sa_sigaction instead of sa_handler for the signal handler to avoid function pointer type mismatch

For the changes in GaudiProfiling it would be good if someone who actually uses this code cross-checks my changes (cc @rmatev). The amount of low-level string manipulations in that code is a bit scary.