The tests 20 and 1322 are using getaddrinfo of libc for resolving. In
eglibc-2.19 there is a memory leakage and invalid free bug which
surfaces in some special circumstances (PF_UNSPEC hint with invalid or
non-existent names). The valgrind runs in testing fail in these
situations.
As the tests 20/1322 are not specific on either protocol (IPv4/IPv6)
this commit changes the hints to IPv4 protocol by passing `--ipv4` flag
on the tests' command line. This prevents the valgrind failures.
While being debated (in #716) and a violation of RFC 7230 section 5.4,
this test verifies that the existing functionality works as intended. It
strips the dot from the host name and uses the host without dot
throughout the internals.
