Drop the doubled word "that".

Signed-off-by: Randy Dunlap <redacted>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
---
 Documentation/networking/ip-sysctl.rst |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20200701.orig/Documentation/networking/ip-sysctl.rst
+++ linux-next-20200701/Documentation/networking/ip-sysctl.rst

@@ -741,7 +741,7 @@ tcp_fastopen - INTEGER
 
 	Default: 0x1
 
-	Note that that additional client or server features are only
+	Note that additional client or server features are only
 	effective if the basic support (0x1 and 0x2) are enabled respectively.
 
 tcp_fastopen_blackhole_timeout_sec - INTEGER