Fix subject grammar

app/mailers/emails/pages_domains.rb

@@ -46,7 +46,7 @@ module Emails
       @domain = domain
       @project = domain.project
 
-      subject_text = _("ACTION REQUIRED: Something went wrong while obtaining Let's Encrypt certificate for GitLab Pages domain '%{domain}'") % { domain: domain.domain }
+      subject_text = _("ACTION REQUIRED: Something went wrong while obtaining the Let's Encrypt certificate for GitLab Pages domain '%{domain}'") % { domain: domain.domain }
       mail(
         to: recipient.notification_email_for(@project.group),
         subject: subject(subject_text)

locale/gitlab.pot

@@ -886,7 +886,7 @@ msgstr ""
 msgid "A user with write access to the source branch selected this option"
 msgstr ""
 
-msgid "ACTION REQUIRED: Something went wrong while obtaining Let's Encrypt certificate for GitLab Pages domain '%{domain}'"
+msgid "ACTION REQUIRED: Something went wrong while obtaining the Let's Encrypt certificate for GitLab Pages domain '%{domain}'"
 msgstr ""
 
 msgid "API Help"

spec/mailers/emails/pages_domains_spec.rb

@@ -104,7 +104,7 @@ describe Emails::PagesDomains do
   end
 
   describe '#pages_domain_auto_ssl_failed_email' do
-    let(:email_subject) { "#{project.path} | ACTION REQUIRED: Something went wrong while obtaining Let's Encrypt certificate for GitLab Pages domain '#{domain.domain}'" }
+    let(:email_subject) { "#{project.path} | ACTION REQUIRED: Something went wrong while obtaining the Let's Encrypt certificate for GitLab Pages domain '#{domain.domain}'" }
 
     subject { Notify.pages_domain_auto_ssl_failed_email(domain, user) }