[BUGFIX] delay displaying Google maps basemap
[BUGFIX] delay displaying Google maps basemap

To have something less awkward, we put the zoomDuration to 0 if there is a Google maps baselayer.
Fixed #316

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