Fix the default form submit icon for current fa

hshassets/templatetags/bulma.py

@@ -60,7 +60,7 @@ def bulma_form(
     form,
     submit_text="OK",
     submit_class="button is-outlined",
-    submit_icon="fa-check",
+    submit_icon="fas fa-check",
     submit_only_once=True,
     form_id=''
 ):