[QUIC] Wrong dcid len in ngx_quic_select_socket_by_dcid

[Gao,Yan(ACG VCP)]

Console client:
~/ngtcp2/examples/client 127.0.0.1 443 https://example.com:443/index.html --dcid=00000000000000166142cdef2ef2ca5e4be5

Bpf log:
           <...>-43083   [001] d.s1 94117.746924: bpf_trace_printk: nginx quic socket len 0x1d
           <...>-43083   [001] d.s1 94117.746936: bpf_trace_printk: nginx quic default route for key 0x16
           <...>-43083   [000] d.s1 94117.764132: bpf_trace_printk: nginx quic socket len 0x1d
           <...>-43083   [000] d.s1 94117.764140: bpf_trace_printk: nginx quic socket selected by key 0x20
           <...>-43083   [000] d.s1 94117.764709: bpf_trace_printk: nginx quic socket selected by key 0x20
           <...>-43083   [000] d.s1 94117.769174: bpf_trace_printk: nginx quic socket selected by key 0x20
           <...>-43083   [000] d.s1 94127.852160: bpf_trace_printk: nginx quic socket selected by key 0x20

The  [nginx quic socket len] is added to show the case, it shoud be 0x12, as 18 bytes

Len should assign after advance_data(1)
Patch and pcap see the attachment

Gao,Yan(ACG VCP)
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