MFH: r448255

www/swish-e: Fix building on FreeBSD 11.1 and HEAD

Newer zlib has its own uncompress2 function, so hot-patch the source to
rename uncompress2 to swishe_uncompress2.

I could not devise a better way to do this at the moment. Cleaner patch
would be welcomed.

Approved by: portmgr (with hat)