TINC: fix invalid memory read (#1512)

```
=================================================================
==19324==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x60600061be96 at pc 0x55b4a4cb4460 bp 0x7ffc7b461a70 sp 0x7ffc7b461a68
READ of size 1 at 0x60600061be96 thread T0
    #0 0x55b4a4cb445f in ndpi_check_tinc /home/ivan/svnrepos/nDPI/src/lib/protocols/tinc.c:105:9
    #1 0x55b4a4cb1888 in ndpi_search_tinc /home/ivan/svnrepos/nDPI/src/lib/protocols/tinc.c:135:5
    #2 0x55b4a4b4a6e1 in check_ndpi_detection_func /home/ivan/svnrepos/nDPI/src/lib/ndpi_main.c:5013:6
    #3 0x55b4a4b4c2d4 in check_ndpi_tcp_flow_func /home/ivan/svnrepos/nDPI/src/lib/ndpi_main.c:5084:12
    #4 0x55b4a4b4bf77 in ndpi_check_flow_func /home/ivan/svnrepos/nDPI/src/lib/ndpi_main.c:5103:12
    #5 0x55b4a4b5dcca in ndpi_detection_process_packet /home/ivan/svnrepos/nDPI/src/lib/ndpi_main.c:5924:15
    #6 0x55b4a4a87734 in packet_processing /home/ivan/svnrepos/nDPI/example/reader_util.c:1519:31
    #7 0x55b4a4a80761 in ndpi_workflow_process_packet /home/ivan/svnrepos/nDPI/example/reader_util.c:2093:10
    #8 0x55b4a4a39c8d in LLVMFuzzerTestOneInput /home/ivan/svnrepos/nDPI/fuzz/fuzz_ndpi_reader.c:107:7
    #9 0x55b4a4a3a46b in main /home/ivan/svnrepos/nDPI/fuzz/fuzz_ndpi_reader.c:179:17
    #10 0x7f69c63760b2 in __libc_start_main /build/glibc-sMfBJT/glibc-2.31/csu/../csu/libc-start.c:308:16
    #11 0x55b4a497954d in _start (/home/ivan/svnrepos/nDPI/fuzz/fuzz_ndpi_reader_with_main+0x61654d) (BuildId: 705ebc5c412d267294a65cb01f03a1f012aeaf20)

0x60600061be96 is located 0 bytes to the right of 54-byte region [0x60600061be60,0x60600061be96)
allocated by thread T0 here:
[...]
```
Found by oss-fuzz:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=46499

0 files changed, 0 insertions, 0 deletions