[BUGFIX] Popup with layer cache enabled don't work
[BUGFIX] Popup with layer cache enabled don't work

Fixed #289

3liz/lizmap-web-client,rldhont/lizmap-web-client,jancelin/lizmap-web-client,makinacorpus/lizmap-web-client,nboisteault/lizmap-web-client,makinacorpus/lizmap-web-client,rldhont/lizmap-web-client,aeag/lizmap-web-client,nboisteault/lizmap-web-client,jancelin/lizmap-web-client,laurentj/lizmap-web-client,makinacorpus/lizmap-web-client,laurentj/lizmap-web-client,aeag/lizmap-web-client,jancelin/lizmap-web-client,laurentj/lizmap-web-client,jancelin/lizmap-web-client,makinacorpus/lizmap-web-client,aeag/lizmap-web-client,aeag/lizmap-web-client,makinacorpus/lizmap-web-client,jancelin/lizmap-web-client,laurentj/lizmap-web-client,3liz/lizmap-web-client,jancelin/lizmap-web-client,nboisteault/lizmap-web-client,rldhont/lizmap-web-client,3liz/lizmap-web-client,rldhont/lizmap-web-client,nboisteault/lizmap-web-client,aeag/lizmap-web-client,3liz/lizmap-web-client