In case the old config already deactivated the newletter, it must be also (#311)

deactivated in the compatibility code.

Co-authored-by: Thorsten Alteholz <thorsten@alteholz.de>
Co-authored-by: Emruz Hossain <hossainemruz@gmail.com>

layouts/partials/footer.html

@@ -9,6 +9,8 @@
 {{/*  Keep backward compatibility for the newsletter function */}}
 {{ if site.Params.newsletter.enable }}
   {{ $newsletterEnabled = true }}
+{{ else }}
+  {{ $newsletterEnabled = false }}
 {{ end }}
 
 {{ if $footerEnabled }}