chore: change issue link to PR

Co-authored-by: Leighton Chen <[email protected]>

Author: Olegt0rr

CHANGELOG.md

@@ -24,7 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#843](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/843))
 
 - `opentelemetry-instrumentation-aiohttp-client` aiohttp: Add custom span name
-  ([#848](https://github.com/open-telemetry/opentelemetry-python-contrib/issues/848))
+  ([#857](https://github.com/open-telemetry/opentelemetry-python-contrib/issues/857))
 
 
 ## [1.8.0-0.27b0](https://github.com/open-telemetry/opentelemetry-python/releases/tag/v1.8.0-0.27b0) - 2021-12-17