fix: show "more call for speaker" button when appropriate (fossasia#3610)

* show call for speaker button when more than 3 events

* comparing callForSpeakersEvents.length instead of callForSpeakersEvents

Author: maze-runnar

Diff for: app/templates/index.hbs

@@ -27,11 +27,13 @@
       {{/each}}
     </div>
     <div class="ui hidden divider"></div>
-    <div class="ui centered grid">
-      <div class="row">
-        {{#link-to "explore" (query-params cfs='open') class='ui blue button'}}{{t 'Show more calls for speakers'}}{{/link-to}}
+    {{#if (gt callForSpeakersEvents.length 3)}}
+      <div class="ui centered grid">
+        <div class="row">
+          {{#link-to "explore" (query-params cfs='open') class='ui blue button'}}{{t 'Show more calls for speakers'}}{{/link-to}}
+        </div>
       </div>
-    </div>
+    {{/if}}
   {{/if}}
 
   {{modals/event-share-modal isOpen=isShareModalOpen event=eventToShare}}