[Code Issue] Unnecessary assignment?

[microwish]

Looks like sometimes this assignment env->kvs = envs; in the body of Environment::Init method in env.h (

ps-lite/include/ps/internal/env.h

Line 36 in db61897

env->kvs = envs;

) is not necessary.

Assume we don't expect to re-assign new environment variables once we already assigned non-empty values, it might be better if we first check whetherEnvironment::kvs is empty, if it's empty, we can do this assignment, otherwise, we won't.

If I'm on the track, would like to make a PR.

Thanks.