+aspell-pl:aspell-pl-libre: isn't built from source

is incorrect. Even if it was, the aspell-pl-libre PKGBUILD doesn't do any changes related to this issue.

My reason for adding aspell-pl-libre was that aspell-pl had source removed after a day and I needed it to build for mips64el, Arch solved this problem by hosting a copy used for newer aspell-pl.