FL-1492: Fixed 404 and 301 URLs in $HOMEPAGE and $SRC_URI for sys-boot/boot-update and...

FL-1492: Fixed 404 and 301 URLs in $HOMEPAGE and $SRC_URI for sys-boot/boot-update and net-misc/keychain

I forgot to escape the $ when writing the message commit...

See https://bugs.funtoo.org/browse/FL-1492