Fix a warning in infinoted when a document is being synced in
Fix a warning in infinoted when a document is being synced in

This causes a session to be created but the InfAdoptedAlgorithm does
not exist yet, so the signal handlers cannot be installed. Instead, wait for
the synchronization to finish before installing the signal handlers on the
algorithm.

gobby/libinfinity,gobby/libinfinity,tyll/libinfinity,tyll/libinfinity,gobby/libinfinity,tyll/libinfinity