update test, due to ifconfig.io certificate changed

Author: Qinghao Shi

tests/tls-socket.log

@@ -11,7 +11,7 @@ Connecting to ifconfig.io
     cert. version     : \d
     serial number     : ([0-9A-F]{2}:)+[0-9A-F]{2}
     issuer name       : C=GB, ST=Greater Manchester, L=Salford,
-    subject name      : OU=Domain Control Validated, OU=PositiveSSL
+    subject name      : 
     issued  on        : 
     expires on        : 
     signed using      : ECDSA with SHA256
@@ -36,4 +36,4 @@ CF-RAY:
 
 \[INFO\]\[TLSW\]: Closing TLS
 \[DBG \]\[TLSW\]: mbedtls_ssl_conf_ca_chain\(\)
-Done
+Done