Merge branch '3.1.15p2-updates' into 'stable-3.1'

FIXES bug mysql-virtual_outgoing_bcc.cf table is not configured with correct...

See merge request ispconfig/ispconfig3!934

install/tpl/mysql-virtual_outgoing_bcc.cf

@@ -5,4 +5,4 @@ table = mail_user
 select_field = sender_cc
 where_field = email
 additional_conditions = and postfix = 'y' and disabledeliver = 'n' and disables$
-hosts = 127.0.0.1
+hosts = {mysql_server_ip}
\ No newline at end of file

install/tpl/mysql-virtual_outgoing_bcc.cf.master

@@ -5,4 +5,4 @@ table = mail_user
 select_field = sender_cc
 where_field = email
 additional_conditions = and postfix = 'y' and disabledeliver = 'n' and disablesmtp = 'n' and sender_cc != ''
-hosts = 127.0.0.1
+hosts = {mysql_server_ip}
\ No newline at end of file