Corrected sign-up URI variable name 📝🛠️

Author: triplingual

schedule/index.html

@@ -65,7 +65,7 @@ <h4><a href="{{site.data.conf.newcomer-dinner.link}}">Newcomer Dinner</a></h4>
                 on the wiki, and we try to mix a few newcomers with a few veterans
                 who can offer an informal introduction to the conference. Great for making new friends!
             </p>
-            {% if site.data.conf.newcomer-dinner.signup-url != '' %}
+            {% if site.data.conf.newcomer-dinner.sign-up-url != '' %}
             <p>
                 <a class="btn ct-btn-light" href="{{ site.data.conf.newcomer-dinner.signup-url }}">Sign-up for the Newcomer Dinner</a>
             </p>