Change support_email env variable name

app/mailers/reporter_mailer.rb

@@ -10,7 +10,7 @@ class ReporterMailer < ActionMailer::Base
   end
 
   def named_maps_near_the_limit(message)
-    mail_to = Cartodb.get_config(:mailer, 'support-email')
+    mail_to = Cartodb.get_config(:mailer, 'support_email')
     if mail_to
       mail to: mail_to, subject: message
     end