board/common: trick pager into using line drawing charachters

This fixes a regression in v24.11.0, introduced in 46dd0c7, where line
drawing characters are not properly displayed in the CLI anymore.

admin@infix:/> show interfaces
INTERFACE       PROTOCOL   STATE       DATA
lo              ethernet   UP          00:00:00:00:00:00
                ipv4                   127.0.0.1/8 (static)
                ipv6                   ::1/128 (static)
br0             bridge
<E2><94><82>               ethernet   UP          02:00:00:00:00:00
<E2><94><82>               ipv4                   169.254.1.3/16 (random)
<E2><94><82>               ipv6                   fe80::ff:fe00:0/64 (link-layer)
<E2><94><9C> swp1          bridge     FORWARDING
<E2><94><9C> swp2          bridge     FORWARDING
<E2><94><9C> swp3          bridge     FORWARDING
<E2><94><9C> swp4          bridge     FORWARDING
<E2><94><9C> swp5          bridge     FORWARDING
<E2><94><9C> swp6          bridge     FORWARDING
<E2><94><9C> swp7          bridge     FORWARDING
<E2><94><9C> swp8          bridge     FORWARDING
<E2><94><9C> swp9          bridge     FORWARDING
<E2><94><94> swp10         bridge     FORWARDING

This is because the raw tty from klish disables IUTF8 and the fact that
it does not source any environment, e.g., /etc/profile.  (We do not have
any locale settings in the enviornment either, but that's a discussion
for another day.)

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

board/common/rootfs/usr/bin/pager

@@ -10,4 +10,6 @@
 #       This is what leaves the contents of the output on screen.
 
 export LESS="-P %f (press h for help or q to quit)"
+export LANG=en_US.UTF-8
+
 less -RISKd -FX "$@"