fix: render empty field for page field. (#220)

recently, changed logic to only render fields if value is present.
however, this caused an issue with page fields, as they are always empty and are updated by wkhtmltopdf.

print_designer/print_designer/page/print_designer/jinja/macros/spantag.html

@@ -24,7 +24,7 @@
 <!-- third Arg is row which is not sent outside table -->
 {% macro span_tag(field, element, row = {}, send_to_jinja = {}) -%}
     {% set span_value = spanvalue(field, element, row, send_to_jinja) %}
-    {%- if span_value -%}
+    {%- if span_value or field.fieldname in ['page', 'topage', 'time', 'date'] -%}
         <span class="{% if not field.is_static and field.is_labelled %}baseSpanTag{% endif %}">
             {% if not field.is_static and field.is_labelled%}
                 <span class="{% if row %}printTable{% else %}dynamicText{% endif %} label-text labelSpanTag" style="user-select:auto; {%if element.labelStyle %}{{convert_css(element.labelStyle)}}{%endif%}{%if field.labelStyle %}{{convert_css(field.labelStyle)}}{%endif%} white-space:nowrap; ">