Update bootstrap-switch.css

Readd this lines to css:

.has-switch.switch-mini i.switch-mini-icons {
  height: 1.20em;
  line-height: 9px;
  vertical-align: text-top;
  text-align: center;
  transform: scale(0.6);
  margin-top: -1px;
  margin-bottom: -1px;
}

because its fixed the HTML-Text mini-switch bug