Make: Install RTS headers in `$libdir/rts/include` not `$libdir/include`
Before we were violating the convention of every other package. This fixes that. It matches the changes made in d5de970d to the location of the files in the repo.
Before we were violating the convention of every other package. This fixes that. It matches the changes made in d5de970d to the location of the files in the repo.