Fix home button link broken in header template

Author: jackycute

public/views/header.ejs

@@ -13,7 +13,7 @@
             <ul class="dropdown-menu list" role="menu" aria-labelledby="menu">
             </ul>
         </div>
-        <a class="navbar-brand pull-left" href="<%- url %>"><i class="fa fa-file-text"></i> HackMD</a>
+        <a class="navbar-brand pull-left" href="<%- url %>/"><i class="fa fa-file-text"></i> HackMD</a>
         <div class="nav-mobile pull-right visible-xs">
             <span class="btn btn-link btn-file ui-upload-image" title="Upload Image" style="display:none;">
                 <i class="fa fa-camera"></i><input type="file" accept="image/*" name="upload" multiple>