Replace .initialism with .text-uppercase.

Author: vudaltsov

Resources/views/Form/bootstrap_4_layout.html.twig

@@ -269,7 +269,7 @@
         <span class="{% if form is not rootform %}invalid-feedback{% else %}alert alert-danger{% endif %} d-block">
             {%- for error in errors -%}
                 <span class="mb-0 d-block">
-                    <span class="initialism form-error-icon badge badge-danger">{{ 'Error'|trans({}, 'validators') }}</span> <span class="form-error-message">{{ error.message }}</span>
+                    <span class="form-error-icon badge badge-danger text-uppercase">{{ 'Error'|trans({}, 'validators') }}</span> <span class="form-error-message">{{ error.message }}</span>
                 </span>
             {%- endfor -%}
         </span>