return None rather than '#' when no match found by slugurl
return None rather than '#' when no match found by slugurl

marctc/wagtail,KimGlazebrook/wagtail-experiment,Tivix/wagtail,chimeno/wagtail,Tivix/wagtail,zerolab/wagtail,Tivix/wagtail,jordij/wagtail,jordij/wagtail,nilnvoid/wagtail,100Shapes/wagtail,tangentlabs/wagtail,lojack/wagtail,FlipperPA/wagtail,Pennebaker/wagtail,hamsterbacke23/wagtail,torchbox/wagtail,takeshineshiro/wagtail,m-sanders/wagtail,darith27/wagtail,nimasmi/wagtail,kurtrwall/wagtail,nilnvoid/wagtail,JoshBarr/wagtail,taedori81/wagtail,FlipperPA/wagtail,rsalmaso/wagtail,zerolab/wagtail,Tivix/wagtail,nealtodd/wagtail,darith27/wagtail,chrxr/wagtail,hamsterbacke23/wagtail,mikedingjan/wagtail,serzans/wagtail,nrsimha/wagtail,Klaudit/wagtail,jnns/wagtail,dresiu/wagtail,kaedroho/wagtail,WQuanfeng/wagtail,WQuanfeng/wagtail,torchbox/wagtail,kurtw/wagtail,chrxr/wagtail,chimeno/wagtail,100Shapes/wagtail,m-sanders/wagtail,kaedroho/wagtail,takeshineshiro/wagtail,mixxorz/wagtail,torchbox/wagtail,mayapurmedia/wagtail,takeshineshiro/wagtail,taedori81/wagtail,dresiu/wagtail,mixxorz/wagtail,helenwarren/pied-wagtail,chrxr/wagtail,thenewguy/wagtail,dresiu/wagtail,zerolab/wagtail,rv816/wagtail,zerolab/wagtail,chrxr/wagtail,tangentlabs/wagtail,gasman/wagtail,Pennebaker/wagtail,nutztherookie/wagtail,benjaoming/wagtail,wagtail/wagtail,iansprice/wagtail,quru/wagtail,iho/wagtail,jorge-marques/wagtail,davecranwell/wagtail,jordij/wagtail,nilnvoid/wagtail,jorge-marques/wagtail,janusnic/wagtail,rsalmaso/wagtail,benjaoming/wagtail,thenewguy/wagtail,mayapurmedia/wagtail,stevenewey/wagtail,gasman/wagtail,nealtodd/wagtail,kurtw/wagtail,gogobook/wagtail,rjsproxy/wagtail,inonit/wagtail,jnns/wagtail,dresiu/wagtail,rjsproxy/wagtail,serzans/wagtail,benemery/wagtail,mjec/wagtail,gogobook/wagtail,quru/wagtail,FlipperPA/wagtail,jorge-marques/wagtail,hamsterbacke23/wagtail,kurtw/wagtail,inonit/wagtail,nutztherookie/wagtail,mjec/wagtail,stevenewey/wagtail,chimeno/wagtail,tangentlabs/wagtail,tangentlabs/wagtail,iho/wagtail,jnns/wagtail,lojack/wagtail,gogobook/wagtail,mephizzle/wagtail,nutztherookie/wagtail,davecranwell/wagtail,100Shapes/wagtail,takeshineshiro/wagtail,thenewguy/wagtail,janusnic/wagtail,timorieber/wagtail,marctc/wagtail,quru/wagtail,wagtail/wagtail,Klaudit/wagtail,nealtodd/wagtail,kurtw/wagtail,bjesus/wagtail,FlipperPA/wagtail,rsalmaso/wagtail,JoshBarr/wagtail,WQuanfeng/wagtail,Pennebaker/wagtail,Toshakins/wagtail,davecranwell/wagtail,benemery/wagtail,rsalmaso/wagtail,iho/wagtail,gasman/wagtail,nrsimha/wagtail,chimeno/wagtail,gasman/wagtail,thenewguy/wagtail,mayapurmedia/wagtail,thenewguy/wagtail,mephizzle/wagtail,mayapurmedia/wagtail,inonit/wagtail,quru/wagtail,takeflight/wagtail,KimGlazebrook/wagtail-experiment,stevenewey/wagtail,bjesus/wagtail,helenwarren/pied-wagtail,helenwarren/pied-wagtail,gasman/wagtail,WQuanfeng/wagtail,iansprice/wagtail,iansprice/wagtail,zerolab/wagtail,wagtail/wagtail,benemery/wagtail,timorieber/wagtail,m-sanders/wagtail,wagtail/wagtail,iansprice/wagtail,willcodefortea/wagtail,kurtrwall/wagtail,stevenewey/wagtail,JoshBarr/wagtail,mephizzle/wagtail,nutztherookie/wagtail,KimGlazebrook/wagtail-experiment,rv816/wagtail,kaedroho/wagtail,rjsproxy/wagtail,darith27/wagtail,hanpama/wagtail,Klaudit/wagtail,rjsproxy/wagtail,Pennebaker/wagtail,m-sanders/wagtail,kurtrwall/wagtail,mjec/wagtail,takeflight/wagtail,torchbox/wagtail,nealtodd/wagtail,taedori81/wagtail,benemery/wagtail,rsalmaso/wagtail,dresiu/wagtail,inonit/wagtail,janusnic/wagtail,mikedingjan/wagtail,marctc/wagtail,nimasmi/wagtail,benjaoming/wagtail,mephizzle/wagtail,Toshakins/wagtail,Klaudit/wagtail,mixxorz/wagtail,KimGlazebrook/wagtail-experiment,janusnic/wagtail,rv816/wagtail,marctc/wagtail,mjec/wagtail,jordij/wagtail,lojack/wagtail,darith27/wagtail,taedori81/wagtail,mikedingjan/wagtail,willcodefortea/wagtail,nimasmi/wagtail,mixxorz/wagtail,timorieber/wagtail,Toshakins/wagtail,nimasmi/wagtail,nrsimha/wagtail,davecranwell/wagtail,serzans/wagtail,kaedroho/wagtail,hamsterbacke23/wagtail,chimeno/wagtail,hanpama/wagtail,iho/wagtail,nrsimha/wagtail,JoshBarr/wagtail,jorge-marques/wagtail,mikedingjan/wagtail,gogobook/wagtail,wagtail/wagtail,willcodefortea/wagtail,kaedroho/wagtail,mixxorz/wagtail,serzans/wagtail,hanpama/wagtail,jnns/wagtail,bjesus/wagtail,takeflight/wagtail,Toshakins/wagtail,takeflight/wagtail,hanpama/wagtail,benjaoming/wagtail,jorge-marques/wagtail,bjesus/wagtail,kurtrwall/wagtail,taedori81/wagtail,timorieber/wagtail,nilnvoid/wagtail,rv816/wagtail,willcodefortea/wagtail