HADOOP-15781. S3A assumed role tests failing due to changed error text in AWS exceptions.

Contributed by Steve Loughran.

Missed final change to ITestAssumeRole

hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/auth/ITestAssumeRole.java

@@ -61,7 +61,6 @@ import static org.apache.hadoop.fs.s3a.auth.RoleTestUtils.*;
 import static org.apache.hadoop.fs.s3a.auth.RoleModel.*;
 import static org.apache.hadoop.fs.s3a.auth.RolePolicies.*;
 import static org.apache.hadoop.fs.s3a.auth.RoleTestUtils.forbidden;
-import static org.apache.hadoop.test.GenericTestUtils.assertExceptionContains;
 import static org.apache.hadoop.test.LambdaTestUtils.*;
 
 /**