add changelog entry for 0.39.1 (cosmos#7321)

Co-authored-by: Marko <[email protected]>

CHANGELOG.md

@@ -328,7 +328,17 @@ pagination.
 * (store) [\#6719](https://github.com/cosmos/cosmos-sdk/6754) Add validity checks to stores for nil and empty keys.
 * (types) \#6897 Add KV type from tendermint to `types` directory.
 
-## [v0.39.0] - 2020-07-20
+## [v0.39.1](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.39.1) - 2020-08-11
+
+### Client Breaking
+
+* (x/auth) [\#6861](https://github.com/cosmos/cosmos-sdk/pull/6861) Remove public key Bech32 encoding for all account types for JSON serialization, instead relying on direct Amino encoding. In addition, JSON serialization utilizes Amino instead of the Go stdlib, so integers are treated as strings.
+
+### Improvements 
+
+* (client) [\#6853](https://github.com/cosmos/cosmos-sdk/pull/6853) Add --unsafe-cors flag.
+
+## [v0.39.0](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.39.0) - 2020-07-20
 
 ### Improvements