Fixed #211: kiwix-serve magnifying icon too small

StackExchange's CSS is setting some property on all elements : margins on <inputs />
and font-size on body that ends-up conflicting with the inserted Kiwix toolbar in
kiwix-serve.

IMO, this is a Kiwix-serve bug and scrapers should not care about how the reader might
affect its content. Related issue: kiwix/libkiwix#394

As a short-term measure, some kiwix-related styles have been overwritten in the scraper.

src/sotoki/templates/base.html

@@ -29,6 +29,8 @@
                 background-repeat: no-repeat;
                 padding-right: 13px;
             }
+            .kiwix_searchform input.ui-autocomplete-input { margin-top: 0; margin-bottom: 0; }
+            .kiwix_searchform { font-size: 14px; }
         </style>
         <script type="text/javascript" src="static/js/jdenticon.min.js" async></script>
         <script type="text/javascript" src="static/js/webp-hero.polyfill.js"></script>