Delete the Contacts/Calender section from the admin page if the user didn't enable Nextcloud

Also, restored the old text in sync-guide.html since the user would only see it if he enabled Nextcloud

management/templates/index.html

@@ -147,9 +147,7 @@
       {% include "aliases.html" %}
       </div>
 
-      <div id="panel_sync_guide" class="admin_panel">
+      <div id="panel_sync_guide" class="admin_panel">{% include "sync-guide.html" %}</div>
-      {% include "sync-guide.html" %}
-      </div>
 
       <div id="panel_web" class="admin_panel">
       {% include "web.html" %}

management/templates/sync-guide.html

@@ -1,7 +1,7 @@
 <div>
 	<h2>Contacts &amp; Calendar Synchronization</h2>
 
-	<p>If you chose to install Nextcloud, then this box can hold your contacts and calendar, just like it holds your email.</p>
+	<p>This box can hold your contacts and calendar, just like it holds your email.</p>
 
 	<hr>
 

setup/management.sh

@@ -85,6 +85,12 @@ unzip -q /tmp/bootstrap.zip -d $assets_dir
 mv $assets_dir/bootstrap-$bootstrap_version-dist $assets_dir/bootstrap
 rm -f /tmp/bootstrap.zip
 
+# Remove the Contacts/Calendar section from the admin page if the user didn't enable Nextcloud
+if [ "${DISABLE_NEXTCLOUD}" == 0 ]; then
+	sed -i '/sync_guide/d' ../management/templates/index.html
+	rm ../management/templates/sync-guide.html
+fi
+
 # Create an init script to start the management daemon and keep it
 # running after a reboot.
 cat > $inst_dir/start <<EOF;