bluetooth.device.conf.5/netgraph.4: remove reference to ng_bt3c(4)

The latter has been removed in 23e124c78b.

share/man/man4/netgraph.4

@@ -36,7 +36,7 @@
 .\" $Whistle: netgraph.4,v 1.7 1999/01/28 23:54:52 julian Exp $
 .\" $FreeBSD$
 .\"
-.Dd November 25, 2013
+.Dd January 9, 2021
 .Dt NETGRAPH 4
 .Os
 .Sh NAME
@@ -1422,7 +1422,6 @@ common networking problems, solved using
 .Xr ng_bluetooth 4 ,
 .Xr ng_bpf 4 ,
 .Xr ng_bridge 4 ,
-.Xr ng_bt3c 4 ,
 .Xr ng_btsocket 4 ,
 .Xr ng_car 4 ,
 .Xr ng_cisco 4 ,

share/man/man5/bluetooth.device.conf.5

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 27, 2008
+.Dd January 9, 2021
 .Dt BLUETOOTH.DEVICE.CONF 5
 .Os
 .Sh NAME
@@ -173,7 +173,6 @@ The
 file should be used to specify configuration parameters overrides for the
 second USB Bluetooth device.
 .Sh SEE ALSO
-.Xr ng_bt3c 4 ,
 .Xr ng_h4 4 ,
 .Xr ng_hci 4 ,
 .Xr ng_l2cap 4 ,