gssdp-client: Use strncpy() instead of strcpy()
gssdp-client: Use strncpy() instead of strcpy()

Limit the length of the string copied so a malicious interface name
cannot overwrite parts of the stack.

Coverity issue: #60337

https://bugzilla.gnome.org/show_bug.cgi?id=730358

GNOME/gssdp,GNOME/gssdp,GNOME/gssdp