python3: remove more $XBPS_CROSS_BASE cruft

Despite this change remove a -I$XBPS_CROSS_BASE/usr/include,
no behaviour was changed since there's another `-I/usr/include` before
that.

No need to bump rev.

srcpkgs/python3/template

@@ -79,6 +79,8 @@ do_install() {
 		sed -i "s/$XBPS_CROSS_TRIPLET-//g" \
 			${DESTDIR}/usr/lib/python${version%.*}/_sysconfigdata_*_*.py \
 			${DESTDIR}/usr/lib/python${version%.*}/config-${version%.*}*/Makefile
+		sed -i -e "s,$XBPS_CROSS_BASE,,g" \
+			${DESTDIR}/usr/bin/python${version%.*}-config
 	fi
 }