libpq leaks memory for SSL connections

I noticed with valgrind how libpq is leaking memory:

at 0x483577F: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x5F645C8: CRYPTO_zalloc (in /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1)
by 0x5E94EEF: BIO_meth_new (in /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1)
by 0x65181EB: ??? (in /usr/lib/x86_64-linux-gnu/libpq.so.5.11)
by 0x651950C: ??? (in /usr/lib/x86_64-linux-gnu/libpq.so.5.11)
by 0x650140F: PQconnectPoll (in /usr/lib/x86_64-linux-gnu/libpq.so.5.11)

Debian doesn't have debuginfo packages for libpq, but looking at the code I think it's pretty clear where the bug is:

my_SSL_set_fd() calls my_BIO_s_socket() which allocates memory with BIO_meth_new(), but nothing ever frees it. Note
thatOpenSSL's BIO_s_socket() returns a const pointer to statically allocated memory.