Update changelog

CHANGELOG.md

@@ -1,3 +1,7 @@
+### [1.10.3] 2020-04-09
+
+  * Fixed invalid --2 flag warning in `self-update` when no channel is requested
+
 ### [1.10.2] 2020-04-09
 
   * Added --1 flag to `self-update` command which can be added to automated self-update runs to make sure it won't automatically jump to 2.0 once that is released
@@ -833,6 +837,7 @@
 
   * Initial release
 
+[1.10.3]: https://github.com/composer/composer/compare/1.10.2...1.10.3
 [1.10.2]: https://github.com/composer/composer/compare/1.10.1...1.10.2
 [1.10.1]: https://github.com/composer/composer/compare/1.10.0...1.10.1
 [1.10.0]: https://github.com/composer/composer/compare/1.10.0-RC...1.10.0