Rev. 1.35 missed fixing the same code on a diff line.

tmcd/freebsd/jail/mkjail.pl

@@ -696,7 +696,7 @@ sub restorerootfs($)
     # Stash the control net IP if not the same as the host IP
     #
     if ($IP ne $hostip) {
-	mysystem("echo $IP >> $path/root/var/emulab/boot/myip");
+	mysystem("echo $IP > $path/root/var/emulab/boot/myip");
     }
 
     # No X11 forwarding.