Update example in TCPSocket.md

Point example to latest version.

Author: Amanda Butler

docs/api/networksocket/TCPSocket.md

@@ -26,7 +26,7 @@ Accepting a connection leaves the original socket in listening mode. You can con
 
 Here is a client example of HTTP transaction over TCPSocket:
 
-[![View code](https://www.mbed.com/embed/?url=https://os.mbed.com/teams/mbed-os-examples/code/mbed-os-example-sockets/)](https://os.mbed.com/teams/mbed-os-examples/code/mbed-os-example-sockets/file/fed3449bba0a/main.cpp)
+[![View code](https://www.mbed.com/embed/?url=https://os.mbed.com/teams/mbed-os-examples/code/mbed-os-example-sockets/)](https://os.mbed.com/teams/mbed-os-examples/code/mbed-os-example-sockets/file/b8986534f233/main.cpp)
 
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