Restore the original style of the fieldset tag in bootstrap

Bootstrap rewrites the style of the fieldset label and the legend label.

Restore the original style settings as follows:

fieldset {
    padding: .35em .625em .75em;
    margin: 0 2px;
    border: 1px solid silver;
 }

legend {
    padding: .5em;
    border: 0;
    width: auto;
    margin-bottom: 0px;
 }