Fix exception when date is nil
Fix exception when date is nil

The @show_only_completed does not filter orders where completed_at is not filled out.
This only solves the ActionView::Template::Error (undefined method `to_date' for nil:NilClass) exception. I18n.l will still drop exception when receives nil instead of a date.
softr8/spree,quentinuys/spree,madetech/spree,lyzxsc/spree,calvinl/spree,welitonfreitas/spree,NerdsvilleCEO/spree,carlesjove/spree,radarseesradar/spree,volpejoaquin/spree,camelmasa/spree,miyazawatomoka/spree,lyzxsc/spree,alvinjean/spree,kewaunited/spree,caiqinghua/spree,radarseesradar/spree,caiqinghua/spree,calvinl/spree,robodisco/spree,rbngzlv/spree,AgilTec/spree,reinaris/spree,groundctrl/spree,carlesjove/spree,wolfieorama/spree,hoanghiep90/spree,grzlus/spree,jaspreet21anand/spree,abhishekjain16/spree,alejandromangione/spree,Engeltj/spree,vmatekole/spree,priyank-gupta/spree,nooysters/spree,dafontaine/spree,zaeznet/spree,orenf/spree,moneyspyder/spree,orenf/spree,pervino/spree,kewaunited/spree,ayb/spree,shekibobo/spree,lyzxsc/spree,brchristian/spree,FadliKun/spree,dafontaine/spree,volpejoaquin/spree,Hawaiideveloper/shoppingcart,DarkoP/spree,berkes/spree,tancnle/spree,TimurTarasenko/spree,KMikhaylovCTG/spree,archSeer/spree,beni55/spree,archSeer/spree,sliaquat/spree,vulk/spree,orenf/spree,gautamsawhney/spree,JuandGirald/spree,joanblake/spree,TimurTarasenko/spree,jeffboulet/spree,abhishekjain16/spree,hoanghiep90/spree,delphsoft/spree-store-ballchair,derekluo/spree,lsirivong/spree,agient/agientstorefront,groundctrl/spree,priyank-gupta/spree,useiichi/spree,joanblake/spree,Kagetsuki/spree,builtbybuffalo/spree,CJMrozek/spree,sliaquat/spree,cutefrank/spree,mindvolt/spree,vulk/spree,tomash/spree,kewaunited/spree,SadTreeFriends/spree,hifly/spree,sunny2601/spree,zamiang/spree,raow/spree,moneyspyder/spree,lsirivong/spree,pulkit21/spree,vcavallo/spree,CiscoCloud/spree,vinsol/spree,vinayvinsol/spree,carlesjove/spree,JuandGirald/spree,siddharth28/spree,NerdsvilleCEO/spree,shekibobo/spree,mleglise/spree,omarsar/spree,lsirivong/spree,pulkit21/spree,useiichi/spree,vulk/spree,JDutil/spree,KMikhaylovCTG/spree,vmatekole/spree,reidblomquist/spree,quentinuys/spree,jeffboulet/spree,shaywood2/spree,dandanwei/spree,ramkumar-kr/spree,DynamoMTL/spree,NerdsvilleCEO/spree,Hawaiideveloper/shoppingcart,archSeer/spree,vinayvinsol/spree,ayb/spree,tesserakt/clean_spree,thogg4/spree,rakibulislam/spree,mindvolt/spree,moneyspyder/spree,mleglise/spree,trigrass2/spree,imella/spree,imella/spree,adaddeo/spree,AgilTec/spree,njerrywerry/spree,Boomkat/spree,grzlus/spree,kewaunited/spree,jasonfb/spree,firman/spree,ayb/spree,reidblomquist/spree,agient/agientstorefront,omarsar/spree,welitonfreitas/spree,jimblesm/spree,vulk/spree,njerrywerry/spree,DynamoMTL/spree,Kagetsuki/spree,DarkoP/spree,vcavallo/spree,nooysters/spree,tancnle/spree,berkes/spree,jaspreet21anand/spree,hoanghiep90/spree,njerrywerry/spree,shaywood2/spree,thogg4/spree,jimblesm/spree,FadliKun/spree,zaeznet/spree,tancnle/spree,karlitxo/spree,yiqing95/spree,hifly/spree,rbngzlv/spree,zamiang/spree,vinsol/spree,CJMrozek/spree,vinayvinsol/spree,orenf/spree,edgward/spree,tesserakt/clean_spree,gregoryrikson/spree-sample,locomotivapro/spree,zaeznet/spree,adaddeo/spree,yiqing95/spree,edgward/spree,alvinjean/spree,jeffboulet/spree,camelmasa/spree,trigrass2/spree,jspizziri/spree,Ropeney/spree,reinaris/spree,reinaris/spree,karlitxo/spree,yushine/spree,reinaris/spree,Hawaiideveloper/shoppingcart,reidblomquist/spree,APohio/spree,adaddeo/spree,lyzxsc/spree,raow/spree,carlesjove/spree,builtbybuffalo/spree,piousbox/spree,progsri/spree,jaspreet21anand/spree,odk211/spree,DarkoP/spree,ramkumar-kr/spree,odk211/spree,siddharth28/spree,tancnle/spree,sfcgeorge/spree,zamiang/spree,wolfieorama/spree,CJMrozek/spree,camelmasa/spree,adaddeo/spree,fahidnasir/spree,gautamsawhney/spree,siddharth28/spree,robodisco/spree,fahidnasir/spree,delphsoft/spree-store-ballchair,softr8/spree,radarseesradar/spree,maybii/spree,vcavallo/spree,quentinuys/spree,thogg4/spree,grzlus/spree,alejandromangione/spree,jeffboulet/spree,jspizziri/spree,JuandGirald/spree,odk211/spree,hoanghiep90/spree,jaspreet21anand/spree,alejandromangione/spree,progsri/spree,rajeevriitm/spree,njerrywerry/spree,locomotivapro/spree,KMikhaylovCTG/spree,karlitxo/spree,TrialGuides/spree,jspizziri/spree,derekluo/spree,joanblake/spree,hifly/spree,madetech/spree,JDutil/spree,maybii/spree,piousbox/spree,CJMrozek/spree,groundctrl/spree,tomash/spree,ahmetabdi/spree,wolfieorama/spree,vcavallo/spree,agient/agientstorefront,gregoryrikson/spree-sample,gregoryrikson/spree-sample,robodisco/spree,zaeznet/spree,miyazawatomoka/spree,edgward/spree,volpejoaquin/spree,FadliKun/spree,cutefrank/spree,sfcgeorge/spree,APohio/spree,madetech/spree,Lostmyname/spree,jparr/spree,pervino/spree,cutefrank/spree,vinsol/spree,jasonfb/spree,yushine/spree,sliaquat/spree,rakibulislam/spree,mindvolt/spree,grzlus/spree,calvinl/spree,tomash/spree,radarseesradar/spree,TrialGuides/spree,FadliKun/spree,Engeltj/spree,azranel/spree,mindvolt/spree,siddharth28/spree,zamiang/spree,shaywood2/spree,TimurTarasenko/spree,SadTreeFriends/spree,DynamoMTL/spree,locomotivapro/spree,Boomkat/spree,thogg4/spree,miyazawatomoka/spree,ramkumar-kr/spree,shekibobo/spree,useiichi/spree,robodisco/spree,TimurTarasenko/spree,trigrass2/spree,Boomkat/spree,builtbybuffalo/spree,useiichi/spree,mleglise/spree,azranel/spree,pulkit21/spree,ramkumar-kr/spree,TrialGuides/spree,patdec/spree,jparr/spree,sunny2601/spree,firman/spree,omarsar/spree,gautamsawhney/spree,abhishekjain16/spree,yushine/spree,rakibulislam/spree,beni55/spree,alejandromangione/spree,AgilTec/spree,DynamoMTL/spree,vinayvinsol/spree,lsirivong/spree,SadTreeFriends/spree,fahidnasir/spree,caiqinghua/spree,Ropeney/spree,delphsoft/spree-store-ballchair,Ropeney/spree,odk211/spree,raow/spree,priyank-gupta/spree,patdec/spree,rajeevriitm/spree,rbngzlv/spree,priyank-gupta/spree,APohio/spree,SadTreeFriends/spree,softr8/spree,shekibobo/spree,yiqing95/spree,alvinjean/spree,calvinl/spree,jparr/spree,NerdsvilleCEO/spree,piousbox/spree,tomash/spree,maybii/spree,mleglise/spree,AgilTec/spree,dafontaine/spree,sfcgeorge/spree,pulkit21/spree,abhishekjain16/spree,brchristian/spree,derekluo/spree,azranel/spree,jasonfb/spree,reidblomquist/spree,pervino/spree,sfcgeorge/spree,vmatekole/spree,sliaquat/spree,vinsol/spree,jasonfb/spree,patdec/spree,dafontaine/spree,sunny2601/spree,jimblesm/spree,rbngzlv/spree,groundctrl/spree,ahmetabdi/spree,Kagetsuki/spree,derekluo/spree,Lostmyname/spree,Engeltj/spree,dandanwei/spree,rajeevriitm/spree,archSeer/spree,Engeltj/spree,tesserakt/clean_spree,KMikhaylovCTG/spree,brchristian/spree,hifly/spree,TrialGuides/spree,progsri/spree,moneyspyder/spree,yiqing95/spree,raow/spree,pervino/spree,quentinuys/spree,patdec/spree,welitonfreitas/spree,volpejoaquin/spree,piousbox/spree,fahidnasir/spree,Ropeney/spree,CiscoCloud/spree,maybii/spree,CiscoCloud/spree,wolfieorama/spree,softr8/spree,dandanwei/spree,DarkoP/spree,karlitxo/spree,alvinjean/spree,ahmetabdi/spree,firman/spree,omarsar/spree,madetech/spree,caiqinghua/spree,edgward/spree,ahmetabdi/spree,vmatekole/spree,rajeevriitm/spree,Hawaiideveloper/shoppingcart,sunny2601/spree,trigrass2/spree,shaywood2/spree,beni55/spree,JuandGirald/spree,CiscoCloud/spree,jspizziri/spree,berkes/spree,Boomkat/spree,delphsoft/spree-store-ballchair,dandanwei/spree,jimblesm/spree,progsri/spree,cutefrank/spree,Kagetsuki/spree,gregoryrikson/spree-sample,brchristian/spree,jparr/spree,beni55/spree,builtbybuffalo/spree,gautamsawhney/spree,firman/spree,ayb/spree,berkes/spree,JDutil/spree,agient/agientstorefront,imella/spree,nooysters/spree,camelmasa/spree,yushine/spree,rakibulislam/spree,APohio/spree,nooysters/spree,welitonfreitas/spree,joanblake/spree,locomotivapro/spree,JDutil/spree,Lostmyname/spree,tesserakt/clean_spree,miyazawatomoka/spree,Lostmyname/spree,azranel/spree