Fix getting parent key value in manage children
Fix getting parent key value in manage children

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