revert: "AWS Encryption SDK 1.9.1 Release" (#389)

This reverts commit 06e9212.

Author: josecorella

CHANGELOG.md

@@ -1,14 +1,5 @@
 # Changelog
 
-### [1.9.1](https://github.com/aws/aws-encryption-sdk-java/compare/v1.9.0...v1.9.1) (2021-10-28)
-
-
-### Maintenance
-
-* Add back removed CiphertextHeaders.deserialize method ([#383](https://github.com/aws/aws-encryption-sdk-java/issues/383)) ([468625d](https://github.com/aws/aws-encryption-sdk-java/commit/468625d03490ed007b5bfc2c20d04cd4973d798e))
-* CI formatting ([#388](https://github.com/aws/aws-encryption-sdk-java/issues/388)) ([129c2c0](https://github.com/aws/aws-encryption-sdk-java/commit/129c2c058fcbfd4b0cf10b2a5ec63dd7f4640a81))
-* update mainline-1.x with new release process ([#385](https://github.com/aws/aws-encryption-sdk-java/issues/385)) ([c55c2d2](https://github.com/aws/aws-encryption-sdk-java/commit/c55c2d205427f62a4c22444bc675cf12d6212e0c))
-
 ## 1.9.0 -- 2021-05-27
 
 * feat: Improvements to the message decryption process. 

pom.xml

@@ -4,7 +4,7 @@
 
     <groupId>com.amazonaws</groupId>
     <artifactId>aws-encryption-sdk-java</artifactId>
-    <version>1.9.1</version>
+    <version>1.9.0</version>
     <packaging>jar</packaging>
 
     <name>aws-encryption-sdk-java</name>