change determine conditions

app/mailers/devise_mailer.rb

@@ -8,7 +8,7 @@ class DeviseMailer < Devise::Mailer
   def subject_for(key)
     subject = super
-    subject << " | #{Gitlab.config.gitlab.email_subject_suffix}" if Gitlab.config.gitlab.email_subject_suffix.length > 0
+    subject << " | #{Gitlab.config.gitlab.email_subject_suffix}" if Gitlab.config.gitlab.email_subject_suffix.present?
     subject
   end
 end

app/mailers/notify.rb

@@ -92,7 +92,7 @@ class Notify < BaseMailer
     subject = ""
     subject << "#{@project.name} | " if @project
     subject << extra.join(' | ') if extra.present?
-    subject << " | #{Gitlab.config.gitlab.email_subject_suffix}" if Gitlab.config.gitlab.email_subject_suffix.length > 0
+    subject << " | #{Gitlab.config.gitlab.email_subject_suffix}" if Gitlab.config.gitlab.email_subject_suffix.present?
     subject
   end