fix GridLayer to not reset if tile zoom didn't change
fix GridLayer to not reset if tile zoom didn't change

stefanocudini/Leaflet,Srikanth4/Leaflet,hyperknot/Leaflet,cmulders/Leaflet,davojta/Leaflet,elfalem/Leaflet,cartant/Leaflet,alex2wong/Leaflet,codeator/Leaflet,Ossehoht/Leaflet,CorainChicago/Leaflet,Trufi/Leaflet,iZucken/Leaflet,webmechanicx/Leaflet,msiadak/Leaflet,Jakobud/Leaflet,tomnod/Leaflet,beni55/Leaflet,mourner/Leaflet,jasonoverland/Leaflet,bbecquet/Leaflet,mourner/Leaflet,fillerwriter/Leaflet,w8r/Leaflet,fillerwriter/Leaflet,tsantacruz/RotationalMarker,wpf500/Leaflet,jmutua2015/Leaflet,webmechanicx/Leaflet,elkingtonmcb/Leaflet,tormi/Leaflet,scaddenp/Leaflet,Srikanth4/Leaflet,jasonoverland/Leaflet,nvoron23/Leaflet,frogcat/Leaflet,wpf500/Leaflet,dhootha/Leaflet,pzdz/Leaflet,dhootha/Leaflet,iOffice/Leaflet,kjell/Leaflet,brah/Leaflet,fredericksilva/Leaflet,rlugojr/Leaflet,msiadak/Leaflet,twoubt/Leaflet,wrrnwng/Leaflet,andrewmartini/Leaflet,cmulders/Leaflet,javimolla/Leaflet,Fil/Leaflet,rlugojr/Leaflet,tbassett44/Leaflet,yohanboniface/Leaflet,fab1an/Leaflet,CapeSepias/Leaflet,nycitt/Leaflet,juliensoret/Leaflet,eriksjaastad/Leaflet,andrewmartini/Leaflet,javimolla/Leaflet,nathancahill/Leaflet,snkashis/Leaflet,grahamthompson/Leaflet,w8r/Leaflet,waeltken/Leaflet,tbassett44/Leaflet,fab1an/Leaflet,codeator/Leaflet,iamjonbradley/Leaflet,jblarsen/Leaflet,olafurr/Leaflet,brah/Leaflet,tomnod/Leaflet,devjoseluis/Leaflet,Trufi/Leaflet,klaftertief/Leaflet,billybonz1/Leaflet,snkashis/Leaflet,hyperknot/Leaflet,davojta/Leaflet,iZucken/Leaflet,RobertoMalatesta/Leaflet,2gis/Leaflet,iOffice/Leaflet,nycitt/Leaflet,Trufi/Leaflet,bbecquet/Leaflet,sambernet/Leaflet,kumy/Leaflet,nikhildhamsaniya/Leaflet,prashen/Leaflet,RyanHickman/Leaflet,elfalem/Leaflet,Jakobud/Leaflet,sellonen/Leaflet,taraszerebecki/Leaflet,pakro/Leaflet,akauppi/Leaflet,psicomante/Leaflet,Ubisense/Leaflet,snkashis/Leaflet,tsantacruz/RotationalMarker,devjoseluis/Leaflet,AP-whitehat/Leaflet,mstahv/Leaflet,klaftertief/Leaflet,Ossehoht/Leaflet,prashen/Leaflet,elkingtonmcb/Leaflet,AndBicScadMedia/Leaflet,davidlukerice/Leaflet,DrillingInfo/Leaflet,nycitt/Leaflet,klaftertief/Leaflet,kumy/Leaflet,bolshoibooze/Leaflet,dhootha/Leaflet,MuellerMatthew/Leaflet,waeltken/Leaflet,northerneyes/Leaflet,elfalem/Leaflet,beni55/Leaflet,bolshoibooze/Leaflet,Andrey-Pavlov/Leaflet,Leaflet/Leaflet,tormi/Leaflet,frogcat/Leaflet,akrzyzanowskino/TeamSE,tomnod/Leaflet,jmutua2015/Leaflet,eriksjaastad/Leaflet,huangsong/Leaflet,grahamthompson/Leaflet,northerneyes/Leaflet,twoubt/Leaflet,yohanboniface/Leaflet,olafurr/Leaflet,RLRR/Leaflet,wancharle/Leaflet,nvoron23/Leaflet,taraszerebecki/Leaflet,msokk/Leaflet,wpf500/Leaflet,huangsong/Leaflet,caiiiycuk/Leaflet,sambernet/Leaflet,davojta/Leaflet,litnerdy/Leaflet,scaddenp/Leaflet,RLRR/Leaflet,pakro/Leaflet,huangsong/Leaflet,mstahv/Leaflet,AndBicScadMedia/Leaflet,cartant/Leaflet,litnerdy/Leaflet,jblarsen/Leaflet,alex2wong/Leaflet,grahamthompson/Leaflet,cartant/Leaflet,waeltken/Leaflet,starsolaris/Leaflet,davidlukerice/Leaflet,eriksjaastad/Leaflet,yohanboniface/Leaflet,taraszerebecki/Leaflet,mbrukman/Leaflet,iamjonbradley/Leaflet,olafurr/Leaflet,codeator/Leaflet,RobertoMalatesta/Leaflet,AP-whitehat/Leaflet,Ossehoht/Leaflet,fredericksilva/Leaflet,akauppi/Leaflet,andrewmartini/Leaflet,MuellerMatthew/Leaflet,fab1an/Leaflet,akrzyzanowskino/TeamSE,mourner/Leaflet,nikhildhamsaniya/Leaflet,nathancahill/Leaflet,nathancahill/Leaflet,lee101/Leaflet,Ubisense/Leaflet,iamjonbradley/Leaflet,kumy/Leaflet,mediasuitenz/Leaflet,pakro/Leaflet,wancharle/Leaflet,AndBicScadMedia/Leaflet,Jakobud/Leaflet,geoloep/Leaflet,tormi/Leaflet,webmechanicx/Leaflet,jasonoverland/Leaflet,w8r/Leaflet,sisou/Leaflet,alex2wong/Leaflet,caiiiycuk/Leaflet,wancharle/Leaflet,devjoseluis/Leaflet,cmulders/Leaflet,msokk/Leaflet,lee101/Leaflet,twoubt/Leaflet,AP-whitehat/Leaflet,CorainChicago/Leaflet,kjell/Leaflet,tbassett44/Leaflet,RyanHickman/Leaflet,sambernet/Leaflet,bolshoibooze/Leaflet,iOffice/Leaflet,akauppi/Leaflet,sisou/Leaflet,sisou/Leaflet,caiiiycuk/Leaflet,Neorth/Leaflet,CorainChicago/Leaflet,javimolla/Leaflet,mbrukman/Leaflet,billybonz1/Leaflet,psicomante/Leaflet,starsolaris/Leaflet,MuellerMatthew/Leaflet,juliensoret/Leaflet,jmutua2015/Leaflet,pzdz/Leaflet,wrrnwng/Leaflet,wrrnwng/Leaflet,DrillingInfo/Leaflet,Leaflet/Leaflet,akrzyzanowskino/TeamSE,beni55/Leaflet,starsolaris/Leaflet,stefanocudini/Leaflet,fredericksilva/Leaflet,tsantacruz/RotationalMarker,Andrey-Pavlov/Leaflet,CapeSepias/Leaflet,fillerwriter/Leaflet,bbecquet/Leaflet,frogcat/Leaflet,mediasuitenz/Leaflet,msiadak/Leaflet,msokk/Leaflet,elkingtonmcb/Leaflet,stefanocudini/Leaflet,Fil/Leaflet,2gis/Leaflet,psicomante/Leaflet,lee101/Leaflet,Neorth/Leaflet,prashen/Leaflet,mediasuitenz/Leaflet,iZucken/Leaflet,mstahv/Leaflet,sellonen/Leaflet,geoloep/Leaflet,hyperknot/Leaflet,Ubisense/Leaflet,thalesfsp/Leaflet,scaddenp/Leaflet,Leaflet/Leaflet,RobertoMalatesta/Leaflet,davidlukerice/Leaflet,pzdz/Leaflet,thalesfsp/Leaflet,Andrey-Pavlov/Leaflet,rlugojr/Leaflet,Srikanth4/Leaflet,Fil/Leaflet,thalesfsp/Leaflet,nikhildhamsaniya/Leaflet,geoloep/Leaflet,sellonen/Leaflet,Neorth/Leaflet,CapeSepias/Leaflet,brah/Leaflet,RyanHickman/Leaflet,billybonz1/Leaflet,litnerdy/Leaflet,jblarsen/Leaflet,mbrukman/Leaflet,2gis/Leaflet,RLRR/Leaflet