Release 4.3.49
Remove #undef MBEDTLS_NET_C from mbedtls_config (#1128) This was needed for windows because the `<windows.h>` include in `threading_alt.h` broke compilation for `net_sockets.c`. However, we can instead define `WIN32_LEAN_AND_MEAN` before including <windows.h> in `threading_alt.h`, which avoids the issue so we can remove this #undef.