proxy-auth-methods.inc: Refer to master passwords, not master users

Author: sirainen

docs/core/config/auth/master_users.md

@@ -6,6 +6,9 @@ dovecotlinks:
     hash: acls
     text: ACL Master Users
   auth_master_users: Master Users
+  auth_master_passwords:
+    hash: master-passwords
+    text: Master Passwords
 ---
 
 # Master Users/Passwords

docs/core/config/proxy/include/proxy-auth-methods.inc

@@ -8,6 +8,6 @@
     * `proxy_mech` is needed only if both OAUTH and cleartext mechanisms
       are enabled.
 
-1. Let Dovecot proxy perform the authentication and login to remote server
-   using the proxy's [[link,auth_master_users]]. This allows client
-   to use also non-cleartext authentication.
+1. Login to the remote server using a [[link,auth_master_passwords,master
+   password]]. This is done by returning `pass=master_secret` extra field. This
+   allows client to use also non-cleartext authentication.