falaise: Fix install error in things2root
falaise: Fix install error in things2root

Patch things2root buildscript to ensure it gets installed into the
directory Falaise knows about for builtin plugins.

xgarrido/homebrew-cadfael,SuperNEMO-DBD/homebrew-cadfael,SuperNEMO-DBD/homebrew-cadfael,xgarrido/homebrew-cadfael