Update recipients of helpdesk, refereeing reminder emails

scipost_django/templates/email/helpdesk/followup_on_ticket.json

@@ -6,11 +6,6 @@
     "bcc": [
 	"admin@",
 	"edadmin@",
-	"refereeing@",
-        "submissions@",
-	"jscaux@",
-	"J.S.Caux@uva.nl",
-	"prof@jscaux.org"
     ],
     "from_name": "SciPost Helpdesk",
     "from_email": "helpdesk@"

scipost_django/templates/email/referees/invite_contributor_to_referee_reminder1.json

 {
     "subject": "SciPost: refereeing request reminder",
     "recipient_list": [
-	    "email_address"
+	"email_address"
     ],
     "bcc": [
 	"submission.editor_in_charge.user.email",

scipost_django/templates/email/referees/remind_referee_deadline_1week.json

 {
     "subject": "SciPost: refereeing deadline approaching",
     "recipient_list": [
-	"jscaux@"
+	"email_address"
     ],
     "bcc": [
         "edadmin@"