fix checksums

deleted all the download files in the cache_distfiles folder and executed:

ls aports/cross/ | xargs pmbootstrap checksum && \
ls aports/device/ | xargs pmbootstrap checksum && \
ls aports/firmware/ | xargs pmbootstrap checksum && \
ls aports/kde/ | xargs pmbootstrap checksum && \
ls aports/maemo/ | xargs pmbootstrap checksum && \
ls aports/main/ | xargs pmbootstrap checksum

a lot of packages resulted having wrong checksums.

Seems like something changed with the .tar.gz files from github.