Remove min-height when data-size is set to a number
Remove min-height when data-size is set to a number

close #1006

nayosx/bootstrap-select,TeleginS/bootstrap-select,coopsource/bootstrap-select,Burick/bootstrap-select,TeleginS/bootstrap-select,QthCN/bootstrap-select,think2011/bootstrap-select,nayosx/bootstrap-select,nhahv/bootstrap-select,tommydevdocs/bootstrap-select,silviomoreto/bootstrap-select,jesenko/bootstrap-select,chengky/bootstrap-select,performancematters/bootstrap-select,emilmoe/bootstrap-select,wearespindle/select3,zhaoyan158567/bootstrap-select,JoachimZ/bootstrap-select,iaesaudi/bootstrap-select,coopsource/bootstrap-select,chengky/bootstrap-select,anhtranqs3/bootstrap4-select,silviomoreto/bootstrap-select,zhaoyan158567/bootstrap-select,bookbrainz/bootstrap-select,wearespindle/select3,iaesaudi/bootstrap-select,bookbrainz/bootstrap-select,JoachimZ/bootstrap-select,performancematters/bootstrap-select,QthCN/bootstrap-select,think2011/bootstrap-select,emilmoe/bootstrap-select,tommydevdocs/bootstrap-select,Burick/bootstrap-select,anhtranqs3/bootstrap4-select,jesenko/bootstrap-select,nhahv/bootstrap-select