Fix unreachable code in URL output handler

[cla7aye15I4nd]

Description

This PR fixes a logical issue in the URL output handler where the final else branch was unreachable due to redundant conditionals.

Problem

The existing code had the following structure:

if (ZSTR_LEN(url_state->url_app.s) != 0) {
    // handle non-empty case
} else if (ZSTR_LEN(url_state->url_app.s) == 0) {
    // handle empty case  
} else {
    // unreachable branch
    *handled_output = NULL;
}

Since ZSTR_LEN() returns a size_t (unsigned integer), the value can only be either "not equal to 0" or "equal to 0". The third else branch was unreachable, making the *handled_output = NULL; assignment dead code.

[Girgias]

Thank you!