Fix broken link to IGN image in attribution
Fix broken link to IGN image in attribution

laurentj/lizmap-web-client,laurentj/lizmap-web-client,rldhont/lizmap-web-client,laurentj/lizmap-web-client,laurentj/lizmap-web-client,nboisteault/lizmap-web-client,nboisteault/lizmap-web-client,rldhont/lizmap-web-client,3liz/lizmap-web-client,rldhont/lizmap-web-client,3liz/lizmap-web-client,3liz/lizmap-web-client,3liz/lizmap-web-client,nboisteault/lizmap-web-client,rldhont/lizmap-web-client,nboisteault/lizmap-web-client