BUG/MINOR: cli: clarify error message about stats bind-process

In 2.7-dev2, "stats bind-process" was removed by commit 94f763b5e
("MEDIUM: config: remove deprecated "bind-process" directives from
frontends") and an error message indicates that it's no more supported.
However it says "stats" is not supported instead of "stats bind-process",
making it a bit confusing.

This should be backported to 2.7.
diff --git a/src/cli.c b/src/cli.c
index 43c36cc..caa837e 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -617,7 +617,7 @@
 		global.cli_fe->maxconn = maxconn;
 	}
 	else if (strcmp(args[1], "bind-process") == 0) {
-		memprintf(err, "'%s' is not supported anymore.", args[0]);
+		memprintf(err, "'%s %s' is not supported anymore.", args[0], args[1]);
 		return -1;
 	}
 	else {