Take the popup container margin-bottom into account to compute autopan (#4768)
Take the popup container margin-bottom into account to compute autopan (#4768)

Fix #4759
msiadak/Leaflet,Leaflet/Leaflet,Trufi/Leaflet,brah/Leaflet,stefanocudini/Leaflet,iZucken/Leaflet,brah/Leaflet,akrzyzanowskino/TeamSE,frogcat/Leaflet,jasonoverland/Leaflet,sisou/Leaflet,AP-whitehat/Leaflet,stefanocudini/Leaflet,davojta/Leaflet,tsantacruz/RotationalMarker,Ubisense/Leaflet,Neorth/Leaflet,AP-whitehat/Leaflet,frogcat/Leaflet,tsantacruz/RotationalMarker,Trufi/Leaflet,geoloep/Leaflet,scaddenp/Leaflet,rlugojr/Leaflet,iOffice/Leaflet,iOffice/Leaflet,jasonoverland/Leaflet,geoloep/Leaflet,CapeSepias/Leaflet,sisou/Leaflet,codeator/Leaflet,Trufi/Leaflet,Leaflet/Leaflet,AP-whitehat/Leaflet,sisou/Leaflet,iZucken/Leaflet,scaddenp/Leaflet,tsantacruz/RotationalMarker,codeator/Leaflet,akrzyzanowskino/TeamSE,msiadak/Leaflet,rlugojr/Leaflet,stefanocudini/Leaflet,davojta/Leaflet,CapeSepias/Leaflet,frogcat/Leaflet,CapeSepias/Leaflet,Leaflet/Leaflet,Neorth/Leaflet,rlugojr/Leaflet,iOffice/Leaflet,codeator/Leaflet,Neorth/Leaflet,scaddenp/Leaflet,jasonoverland/Leaflet,msiadak/Leaflet,brah/Leaflet,davojta/Leaflet,akrzyzanowskino/TeamSE,geoloep/Leaflet,Ubisense/Leaflet,Ubisense/Leaflet,iZucken/Leaflet