[thiagosouza84]

Fixes #4298.

build_prack_dialog_info() (modules/dialog/dlg_req_within.c) had two problems with the PRACK route set:

1. It was printed from all the Record-Route headers of the reliable 18x (skip_rrs = 0), including the proxy's own. As a result, the PRACK was routed to the proxy itself. The 2xx path (push_reply_in_dialog()) skips from_rr_nb + added_rr.
2. It was parsed with parse_rr_body(rr_set.s, ...) into td->route_set, whose rr_t entries point into rr_set.s. That buffer is pkg_free()d at the end of the function, before tm prints the request, so the Route went out corrupted (e.g. Route: 172.30.50.10.0.10;lr;did=...>).

The fix:

• skips the RRs received with the INVITE plus the ones added on the reply's branch, as for the 2xx. This does not apply under topology hiding, where the 2xx path doesn't skip either;
• gives td its own copy of the route set (duplicate_rr()), which free_tm_dlg() releases as before.

Tests: OpenSIPS/sipssert-opensips-tests#38 (dialog/21.prack-uac-auto-rr-in-18x, dialog/22.prack-uac-auto-rr-in-18x-downstream).

Local results (arm64 source builds):

	master 6abfdcc	this PR
dialog 01–18	PASS	PASS
21 (only the proxy's RR in the 180, PRACK with no Route)	FAIL	PASS
22 (downstream proxy RR, PRACK with only that Route)	FAIL (timeout)	PASS
topology-hiding, record-route	PASS	PASS