chore(doc): fixed issue number

Author: bednar

CHANGELOG.md

@@ -1,7 +1,7 @@
 ## 1.3.0 [unreleased]
 
 ### Features
-1. [#49](https://github.com/influxdata/influxdb-client-python/issues/50): Implemented default tags
+1. [#50](https://github.com/influxdata/influxdb-client-python/issues/50): Implemented default tags
 
 ### API
 1. [#47](https://github.com/influxdata/influxdb-client-python/pull/47): Updated swagger to latest version