update /layouts/header.html template (reduce size of site header).

The <a> tag would stretch across the top of the page and it made it hard to
click in an 'empty' space on the page. It was, also, confusing when the page
would change to the home page when you were not paying attention whilst clicking.

templates/layouts/header.html

@@ -110,8 +110,8 @@
     </div>
     {% endif %}
 
-    <a class="fe-site-header"
+    <div class="fe-site-header">
-       title="Click to view the site's home page"
+    <a title="Click to view the site's home page"
        href="/">
         {% ifequal system-data.first.enable-site-logo 1 %}
         <img alt="{{system-data.first.site-name}}"
@@ -119,6 +119,7 @@
         {% endifequal %}
         <h1>{{system-data.first.site-name}}</h1>
     </a>
+    </div>
 
     <nav>
         {% for page in system-data.last.first %}