docs: update CHANGELOG.md

Co-authored-by: Robert Hajek <[email protected]>

Author: bednar

CHANGELOG.md

@@ -2,7 +2,7 @@
 
 ### Features
 1. [#203](https://github.com/influxdata/influxdb-client-python/pull/203): Configure a client via TOML file
-1. [#215](https://github.com/influxdata/influxdb-client-python/pull/215): Allowed to configure a connection pool maxsize
+1. [#215](https://github.com/influxdata/influxdb-client-python/pull/215): Configure a connection pool maxsize
 
 ### Bug Fixes
 1. [#206](https://github.com/influxdata/influxdb-client-python/pull/207): Use default (system) certificates instead of Mozilla's root certificates (certifi.where())