  Fix for https://github.com/pbiering/ipv6calc/issues/25

--- a/tools/ipv6calc-db-update.sh.in~	2021-05-18 20:42:27.000000000 +0200
+++ b/tools/ipv6calc-db-update.sh.in	2021-05-21 09:30:39.913996788 +0200
@@ -37,7 +37,7 @@
 END
 }
 
-skip_download=true
+skip_download=false
 update=false
 while getopts "D:ush\?" opt; do
 	case $opt in
