build: remove echo-server from win32 build.

Author: Christian Hergert

CMakeLists.txt

@@ -244,8 +244,6 @@ mongoc_add_test(test-sharded-cluster FALSE
    ${SOURCE_DIR}/tests/test-sharded-cluster.c
    ${SOURCE_DIR}/tests/mongoc-tests.c
    ${SOURCE_DIR}/tests/ha-test.c)
-mongoc_add_test(echo-server FALSE
-   ${SOURCE_DIR}/tests/echo-server.c)
 
 mongoc_add_test(test-libmongoc FALSE ${test-libmongoc-sources})
 add_test(NAME test-libmongoc COMMAND test-libmongoc -f -p)