kvm: added back ipv6 parameter
Revert "kvm: added back ipv6 parameter"

This reverts commit 01190bdab5e47bb63fce2fc0dd0406bb89e6d196.
Fix json schemas.
version up : groonga 4.0.7 and mroonga 4.07.
version up : wget 1.16.
version up : gettext 0.19.3.