Small error in openconnect.8

[Björn Ketelaars]

openconnect.8 discusses 'basemtu' as option. Unfortunately this option is not
recognized. A quick glance in the source learned that 'base-mtu' should be
used.

Signed-off-by: Björn Ketelaars <bjorn.ketelaars at hydroxide.nl>

diff --git openconnect.8.in openconnect.8.in
index 1968bd0..b441ac7 100644
--- openconnect.8.in
+++ openconnect.8.in
@@ -25,7 +25,7 @@ openconnect \- Connect to Cisco AnyConnect VPN
 .OP \-U,\-\-setuid user
 .OP \-\-csd\-user user
 .OP \-m,\-\-mtu mtu
-.OP \-\-basemtu mtu
+.OP \-\-base\-mtu mtu
 .OP \-p,\-\-key\-password pass
 .OP \-P,\-\-proxy proxyurl
 .OP \-\-proxy\-auth methods
@@ -215,7 +215,7 @@ Request
 .I MTU
 from server as the MTU of the tunnel.
 .TP
-.B \-\-basemtu=3DMTU
+.B \-\-base\-mtu=3DMTU
 Indicate
 .I MTU
 as the path MTU between client and server on the unencrypted network. Newer