DOC: configuration: add missing index entries for tune.pool-{low,high}-fd-ratio
These two keywords didn't have an entry in the index. They were added in
2.0 by commit 88698d966 ("MEDIUM: connections: Add a way to control the
number of idling connections.") so this must be backported to 2.0.
diff --git a/doc/configuration.txt b/doc/configuration.txt
index 78439aa..de7384b 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -693,6 +693,8 @@
- tune.maxrewrite
- tune.pattern.cache-size
- tune.pipesize
+ - tune.pool-high-fd-ratio
+ - tune.pool-low-fd-ratio
- tune.rcvbuf.client
- tune.rcvbuf.server
- tune.recv_enough