fix: change MBEDTLS_SSL_OUT_CONTENT_LEN to 4096

Set MBEDTLS_SSL_OUT_CONTENT_LEN to a smaller number when TLS 1.3 is
enabled, becase MBEDTLS_SSL_MAX_FRAGMENT_LENGTH is not supported
in TLS 1.3

Author: Taowyoo

mbedtls-sys/build/config.rs

@@ -421,6 +421,9 @@ pub const FEATURE_DEFINES: &'static [(&'static str, CDefine)] = &[
     ("tls13",                 ("MBEDTLS_SSL_TLS1_3_TICKET_AGE_TOLERANCE",                    DefinedAs("6000"))),
     ("tls13",                 ("MBEDTLS_SSL_TLS1_3_TICKET_NONCE_LENGTH",                     DefinedAs("32"))),
     ("tls13",                 ("MBEDTLS_SSL_TLS1_3_DEFAULT_NEW_SESSION_TICKETS",             DefinedAs("1"))),
+    // TODO: This is added becuase of issue: #293
+    // Once upstream support MBEDTLS_SSL_RECORD_SIZE_LIMIT extension for TLS 1.3, we need to remove this
+    ("tls13",                 ("MBEDTLS_SSL_OUT_CONTENT_LEN",                                DefinedAs("4096"))),
 ];
 
 #[cfg_attr(rustfmt, rustfmt_skip)]