Commit 14c06e44 for quagga.net

commit 14c06e44cf8ea99adeccb80a069a3e3171f52c10
Author: Timo Teräs <timo.teras@iki.fi>
Date:   Sun Jul 19 18:08:50 2020 +0300

    nhrpd: add reference to net.ipv4.ip_forward_use_pmtu=1 thread

    Add a mailing list reference regard net.ipv4.ip_forward_use_pmtu=1.

diff --git a/nhrpd/README.kernel b/nhrpd/README.kernel
index 3fe1f65f..eb096554 100644
--- a/nhrpd/README.kernel
+++ b/nhrpd/README.kernel
@@ -34,6 +34,7 @@ This list tries to collect them to one source of information:
     commit "ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing"
   Workaround:
     Set sysctl net.ipv4.ip_forward_use_pmtu=1
+    See: https://marc.info/?t=143636239500003&r=1&w=2 for details
     (Should fix kernel to have this by default on for tunnel devices)

 - subtle path mtu mishandling issues