fix the path of the 'nano' command in the toolbox container

it seems that debian moved '/usr/bin/nano' to '/bin/nano'

toolbox/files/usr/local/bin/toolbox-update

 #!/bin/sh
 
-BIN_COMMANDS="ps less nc.openbsd"
+BIN_COMMANDS="ps less nano nc.openbsd"
 # FIXME gvim is disabled because it is broken:
 # 	- missing fonts (see fonts.conf(5))
 #       - missing icons 
-USR_BIN_COMMANDS="scp ssh sshd ssh-keygen xauth top vi vim nano nc"
+USR_BIN_COMMANDS="scp ssh sshd ssh-keygen xauth top vi vim nc"
 
 set -ex