[DOC] fix typo in the queue() definition (backend, not frontend)
Reported by Benjamin Pineau.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 9c1ea51..619e4fa 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -6500,7 +6500,7 @@
"monitor fail".
queue <integer>
-queue(frontend) <integer>
+queue(backend) <integer>
Returns the total number of queued connections of the designated backend,
including all the connections in server queues. If no backend name is
specified, the current one is used, but it is also possible to check another