[DOC] fix typos about bind-process syntax

Reported by Tijn Lambrechtsen.
(cherry picked from commit 365cddc61dec824c7edcfca7cf974222a42f4896)
diff --git a/doc/configuration.txt b/doc/configuration.txt
index d7f81f4..d05ad9e 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -1453,15 +1453,15 @@
   Example :
         listen app_ip1
             bind 10.0.0.1:80
-            bind_process odd
+            bind-process odd
 
         listen app_ip2
             bind 10.0.0.2:80
-            bind_process even
+            bind-process even
 
         listen management
             bind 10.0.0.3:80
-            bind_process 1 2 3 4
+            bind-process 1 2 3 4
 
   See also : "nbproc" in global section.