[3.13] community/tinc-pre: upgrade to 1.1pre18

backport; also changed maintainer as master branch

some major fix

• Fix segfault when failing to read random numbers.
• fix send_udp_probe_packet segfault https://github.com/gsliepen/tinc/issues/227
• fix find_cached segfault https://github.com/gsliepen/tinc/issues/226 Don't keep an address cache in an outgoing_t.
• Try harder to connect to unreachable nodes.
• fix: use EVP_DecryptUpdate while decrypting
• Prevent large amounts of UDP probes being sent consecutively. manuall patched
• Fix segfault when dest->mtu is 0.