Fix dualdate to start at minDate if no dateValue is given.
Fix dualdate to start at minDate if no dateValue is given.

Centeva/ngx-datepicker,Centeva/ngx-datepicker,Centeva/ng2-datepicker,Centeva/ng2-datepicker,anhany/ngx-datepicker,anhany/ngx-datepicker,Centeva/ngx-datepicker,Centeva/ng2-datepicker,anhany/ngx-datepicker