backoffice: limit height of fields filter (#1671)

wcs/backoffice/root.ptl

@@ -222,7 +222,7 @@ class FormPage(Directory):
             '<noscript><input type="submit" value="%s"/></noscript>' % _('Refresh')
 
         '<h3>%s</h3>' % _('Fields to display')
-        '<ul>'
+        '<ul id="fields-filter">'
         for field in self.get_formdef_fields():
             if not hasattr(field, str('get_view_value')):
                 continue

wcs/qommon/static/css/dc2/admin.css

@@ -664,6 +664,11 @@ div#page-links {
 	margin: 1em 0;
 }
 
+ul#fields-filter {
+	overflow: auto;
+	max-height: 350px;
+}
+
 /* Styling for workflow graphs */
 
 svg {