fix: jinja2 template syntax in artery index

soleprint/artery/index.html

@@ -443,14 +443,7 @@
                 <div
                     class="vein{% if vein.status == 'live' or vein.status == 'building' %} active{% else %} disabled{% endif %}{% if loop.first %} selected{% endif %}"
                     data-tab="{{ vein.slug }}"
-                    {%
-                    if
-                    vein.status=""
-                    ="planned"
-                    %}data-disabled="true"
-                    {%
-                    endif
-                    %}
+                    {% if vein.status == "planned" %}data-disabled="true"{% endif %}
                 >
                     <h3>{{ vein.title }}</h3>
                 </div>