consider RFC signoff requirements

[Licenser]

Currently, RFCs state the following requirement

Before actually entering FCP, *all* members of the subteam must sign off; 
this is often the point at which many subteam members first review the RFC

This can become problematic if a subteam member becomes unavailable, due to vacation, health, or personal reasons. It is worth considering how to phrase this requirement in a way that is accommodating for team members' lives and other unforeseen circumstances.