Fix RVM / Capistrano integration

Newer versions of RVM (sometime after 1.1.4 and before 1.15.8) changed
up how RVM integrates with Capistrano. Deploy systems now need the
rvm-capistrano gem installed into their RVM environment but this borks
the $:.unshift (aka $LOAD_PATH.unshift) initial line. Kill the line so
we don't have issues as RVM continues to update...