OO-5315: remove old trick for bootstrap and older Firefox

src/main/webapp/static/themes/light/modules/_bootstrap.scss

@@ -117,13 +117,6 @@ td.text-left>div.form-inline>label.checkbox-inline>input[type='checkbox'] {
 	position: relative;
 }
 
-/* http://stackoverflow.com/questions/17408815/fieldset-resizes-wrong-appears-to-have-unremovable-min-width-min-content/17863685#17863685 */
-@-moz-document url-prefix() {
-    fieldset {
-        display: table-cell;
-    }
-}
-
 /* 
 	iOS: prevent browser zoom when selecting a form (iOS zooms when input element font size < 16px but does not zoom back)
 	https://stackoverflow.com/questions/2989263/disable-auto-zoom-in-input-text-tag-safari-on-iphone