abuild: use only sha512sum

use only the strongest hash. this simplifies apkbuilds a bit.

abuild.in

@@ -1907,16 +1907,6 @@ checksum() {
 		files="$files $(filename_from_uri $s)"
 	done
 
-	# for compatibility/backporting reasons we still add md5sum
-	msg "Updating the md5sums in APKBUILD..."
-	md5sums="$(cd "$srcdir" && md5sum $files)" || die "md5sum failed"
-	echo "md5sums=\"$md5sums\"" >>"$APKBUILD"
-
-	msg "Updating the sha256sums in APKBUILD..."
-	sha256sums="$(cd "$srcdir" && sha256sum $files)" \
-		|| die "sha256sum failed"
-	echo "sha256sums=\"$sha256sums\"" >>"$APKBUILD"
-
 	msg "Updating the sha512sums in APKBUILD..."
 	sha512sums="$(cd "$srcdir" && sha512sum $files)" \
 		|| die "sha512sum failed"