CDRIVER-4698 remove excess duplicate call (#1357)

This is not a bug. The duplicate call to `_mongoc_http_response_cleanup` does not currently result in a double free.
Nonetheless, the duplicate call may result in a double free if the implementation of `_mongoc_http_send` changes in the future.

Author: kevinAlbs

src/libmongoc/src/mongoc/mcd-azure.c

@@ -180,7 +180,6 @@ mcd_azure_access_token_from_imds (mcd_azure_access_token *const out,
       &req, opt_imds_host, opt_port, opt_extra_headers);
 
    if (!_mongoc_http_send (&req.req, 3 * 1000, false, NULL, &resp, error)) {
-      _mongoc_http_response_cleanup (&resp);
       goto fail;
    }