docs: delete NRD manpage from toctree

refs #2489

Change-Id: I98bf2bbd6895b1c64c3cd4dc24abc493969a0de4
diff --git a/docs/manpages.rst b/docs/manpages.rst
index 4d8ee12..f945bf1 100644
--- a/docs/manpages.rst
+++ b/docs/manpages.rst
@@ -5,7 +5,6 @@
 
 .. toctree::
    manpages/nfd
-   manpages/nrd
    manpages/nfdc
    manpages/nfd-status
    schema