test: move net reconnect error test to sequential

The usage of common.PORT could cause undesired port collisions when run
in parallel. The following test was moved to sequential.
test-net-reconnect-error.js

PR-URL: https://github.com/nodejs/node/pull/13033
Refs: https://github.com/nodejs/node/issues/12376


Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>