build-sys: make lxml required when generating indices

Since the manpage indices generated without lxml would be missing some
parts, it doesn't make sense to keep lxml optional anymore.

1 files changed, 1 insertions, 1 deletions

diff --git a/README b/README
index 509b45f6f..9aa63128d 100644
--- a/README
+++ b/README
@@ -133,8 +133,8 @@ REQUIREMENTS:
         gperf
         gtkdocize (optional)
         python (optional)
+        python-lxml (optional, but required to build the indices)
         sphinx (optional)
-        python-lxml (entirely optional)
 
         When systemd-hostnamed is used, it is strongly recommended to
         install nss-myhostname to ensure that, in a world of