luci-mod-system: add current host to reset reconnect

luci-mod-system: add current host to reset reconnect

When performing a sysupgrade without keeping settings, the reconnect
logic only tries the hardcoded 192.168.1.1 and openwrt.lan. This fails
silently when the device uses a different static IP.

Prepend window.location.host to the reconnect target list, keeping the
existing defaults as fallbacks. This matches the behavior already used
when settings are kept.

Common use case: custom images built with the OpenWrt Image Builder and
pre-configured static IPs land on a known address that differs from the
defaults after a factory reset. The current host is the most likely
correct target since the user is already connected to it.

Signed-off-by: Zadkiel AHARONIAN <redacted>