fix bug for firefox
fix bug for firefox

musikele/datetimepicker,rachmann/datetimepicker,akaramires/datetimepicker,jinghm318/datetimepicker,confile/datetimepicker,nitishdola/material-management-systems,andrewmnlv/datetimepicker,andrewmnlv/datetimepicker,OakNinja/datetimepicker,xdan/datetimepicker,nitishdola/material-management-systems,drew-y/meteor-datetimepicker,jCaptain/datetimepicker,drew-y/meteor-datetimepicker,WWWSpider/datetimepicker,confile/datetimepicker,malko/datetimepicker,Telem/datetimepicker,Zalmoxisus/momentjs-datetimepicker,xtratio/datetimepicker,jinghm318/datetimepicker,jitbit/datetimepicker,akaramires/datetimepicker,irosle/datetimepicker,musikele/datetimepicker,nitishdola/material-management-systems,OakNinja/datetimepicker,Jazzo/datetimepicker,malko/datetimepicker,irosle/datetimepicker,xdan/datetimepicker,jitbit/datetimepicker,jCaptain/datetimepicker,geneanet/datetimepicker,Telem/datetimepicker,richellyitalo/datetimepicker,WWWSpider/datetimepicker,richellyitalo/datetimepicker,Zalmoxisus/momentjs-datetimepicker,xtratio/datetimepicker,nitishdola/material-management-systems,rachmann/datetimepicker,Jazzo/datetimepicker