[fix] w3m submit button text display

searx/static/css/style.css

     opacity: 0.8;
     width: 28px;
     height: 30px;
+    font-size: 0;
 }
 
 #results { margin: 10px; padding: 0; }

searx/templates/search.html

 <form method="post" action="/" id="search_form">
   <div id="search_wrapper">
     <input type="text" id="q" class="q" name="q" tabindex="1" autocomplete="off" {% if q %}value="{{ q }}"{% endif %}/>
-    <input type="submit" value="" id="search_submit" />
+    <input type="submit" value="search" id="search_submit" />
   </div>
   {% include 'categories.html' %}
 </form>