Merge pull request #974 from henrytill/README-fix-typo-server-example

README: fix typo in server_example invocation

README.md

@@ -424,7 +424,7 @@ EOF
 ```
 then build and execute the example with
 ```
-$ dune exec ./client_example.exe
+$ dune exec ./server_example.exe
 ```
 
 As in the previous example, here we are explicitly mentioning conduit-lwt to