Fixing main and application port structs file descriptor init.
Fixing main and application port structs file descriptor init.

Correct value for non-initialized file descriptor is -1, because most of the
checks in libunit compares file descriptor with -1 before performing an
action.  Using 0 as default value, may cause to close file descriptor #0, this
may affect application logic.

It is not required to list this patch in changelog because impact is not seen
by end users.

nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit,nginx/unit