[Bugfix] For embedded layers, verifying the values are not empty
[Bugfix] For embedded layers, verifying the values are not empty

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