Update overview.md

Updated China North 3 Zone Redundancy

Author: kabharati

articles/postgresql/flexible-server/overview.md

@@ -90,7 +90,7 @@ One advantage of running your workload in Azure is global reach. The flexible se
 | Central India | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: |
 | Central US | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: |
 | China East 3 | :heavy_check_mark: | :x: | :heavy_check_mark: | :x: | 
-| China North 3 | :heavy_check_mark: | :x: | :heavy_check_mark: | :x: | 
+| China North 3 | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | :x: | 
 | East Asia | :heavy_check_mark: | :heavy_check_mark: ** | :heavy_check_mark: | :heavy_check_mark: |
 | East US | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: |
 | East US 2 | :heavy_check_mark: | :x: $ | :heavy_check_mark: | :heavy_check_mark: |