Fix uniweb ecomail integration, center form

shared/templates/styleguide2/form_page.html

@@ -84,7 +84,11 @@
         </div>
       {% endfor %}
 
-      {% include "styleguide2/includes/atoms/buttons/round_button_form.html" with show_arrow_on_hover=True text="Odeslat" %}
+      {% if page.submission_button_text %}
+        {% include "styleguide2/includes/atoms/buttons/round_button_form.html" with show_arrow_on_hover=True text=page.submission_button_text %}
+      {% else %}
+        {% include "styleguide2/includes/atoms/buttons/round_button_form.html" with show_arrow_on_hover=True text="Odeslat" %}
+      {% endif %}
     </form>
 
     {% for block in page.content_after %}