Fix overriding the predefined ratelimiter by WithGlobalRateLimit

[kiokuless]

Proposed changes

I noticed that the e.rateLimiter set in WithGlobalRateLimit was overwritten in sdk_private.go and the RPS was unlimited every time, so I fixed it.

I ran WithGlobalRateLimit(10, time.Second) in examples/simple/simple.go to verify that the RPS is correctly below 10.

Checklist

• Pull request is created against the dev branch
• All checks passed (lint, unit/integration/regression tests etc.) with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[Mzack9999]

lgtm - It doesn't seem the case if the ratelimit is correctly scoped and closed, but I think this might create gc glitches with internal ephemeral objects as in #4836