fix: empty search shows None (#19055) (#19056)

[skip ci]

(cherry picked from commit 83f591e)

Co-authored-by: Ankush Menat <ankush@frappe.io>

frappe/templates/includes/navbar/navbar_search.html

@@ -2,7 +2,7 @@
 	<li>
 		<form action='/search'>
 		<input name='q' class='form-control navbar-search' type='text'
-			value='{{ frappe.form_dict.q|e or ''}}'
+			value='{{ frappe.form_dict.q|e if frappe.form_dict.q else ''}}'
 			{% if not frappe.form_dict.q%}placeholder="{{ _("Search...") }}"{% endif %}>
 		</form>
 	</li>