Take `this.zoomControl` into account
Take `this.zoomControl` into account

Rather than relying on the map's zoomControl, which is not always set, use
`this.zoomControl`

DrillingInfo/Leaflet.loading,DrillingInfo/Leaflet.loading,NBTSolutions/Leaflet.loading,ebrelsford/Leaflet.loading,NBTSolutions/Leaflet.loading,laurenancona/Leaflet.loading