DOC: specify that stats socket doc (section 9.2) is in management

Commit 44aed90ce1 moved the stats socket
documentation from config to management but the remaining references to
section 9.2 were not updated; improve it to be less confusing.

Signed-off-by: Kevin Decherf <kevin@kdecherf.com>

doc/configuration.txt

@@ -859,7 +859,8 @@ stats socket [<address:port>|<path>] [param*]
   Binds a UNIX socket to <path> or a TCPv4/v6 address to <address:port>.
   Connections to this socket will return various statistics outputs and even
   allow some commands to be issued to change some runtime settings. Please
-  consult section 9.2 "Unix Socket commands" for more details.
+  consult section 9.2 "Unix Socket commands" of Management Guide for more
+  details.
 
   All parameters supported by "bind" lines are supported, for instance to
   restrict access to some users or their access rights. Please consult
@@ -4233,7 +4234,7 @@ load-server-state-from-file { global | local | none }
 
   The format of the file is versionned and is very specific. To understand it,
   please read the documentation of the "show servers state" command (chapter
-  9.2).
+  9.2 of Management Guide).
 
   Arguments:
     global     load the content of the file pointed by the global directive