drop which when sourcing charms.reactive.sh
drop which when sourcing charms.reactive.sh

This feels so weird...  source & which have always been like PB & J for me.  Alas, bruzer seems to know what he's talking about here.  I verified `source` does indeed search PATH, making `which` superfluous.
juju-solutions/charms.reactive,juju-solutions/charms.reactive