net: lwip: wget: fix legacy syntax

net: lwip: wget: fix legacy syntax

Commit 356011f7ac25 ("lwip: fix code style issues") has inadvertently
broken the support for the legacy syntax:

 => wget 192.168.0.16:test.bin
 invalid uri, no file path
 Invalid URL. Use http(s)://

The reason is two calls to strncpy() were replaced by strlcpy() without
paying attention to the fact that they are not equivalent in the present
case. Since we are using a character counter (n) and since we do not
depend on having a properly null-terminated string at each step in the
parsing, strlcpy() is not justified and strncpy() is the right tool for
the job. So use it again.

Reported-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>