Adding a class of .searchbar to your input's parent container will disable validation on that input. In this example, we're using input button groups, found in the groups documentation.
<form class="searchbar">
<div class="input-group">
<input class="form-control" placeholder="Search ..." type="text">
<span class="input-group-btn">
<button class="btn btn-secondary" type="submit">
<svg class="icon icon-1" viewBox="0 0 256 256">
<use xlink:href="/assets/svgs/icons.svg#search"></use>
</svg>
</button>
</span>
</div>
</form>