Cargo undeploy does not work with Tomcat 8

The command 'mvn cargo:undeploy', as documented at [1], no longer works with Tomcat 8. The Cargo plugin complains about an incorrect username and password.

Steps to reproduce:
1. start the archetypes CMS
2. cd site
3. mvn cargo:undeploy

Expected: the site webapp is undeployed
Actual: the following error message is shown:

[INFO] — cargo-maven2-plugin:1.4.11:undeploy (default-cli) @ gettingstarted-site —
[INFO] [DeployerUndeployMojo] Resolved container artifact org.codehaus.cargo:cargo-core-container-tomcat:jar:1.4.11 for container tomcat8x
[INFO] [mcat8xRemoteDeployer] Undeploying [/home/user/projects/archetypes/website/target/gettingstarted/site/target/site.war]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.857 s
[INFO] Finished at: 2015-01-06T10:35:14+01:00
[INFO] Final Memory: 14M/304M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.codehaus.cargo:cargo-maven2-plugin:1.4.11:undeploy (default-cli) on project gettingstarted-site: Execution default-cli of goal org.codehaus.cargo:cargo-maven2-plugin:1.4.11:undeploy failed: Failed to undeploy [/home/user/projects/archetypes/website/target/gettingstarted/site/target/site.war]: The username and password you provided are not correct (error 401): Server returned HTTP response code: 401 for URL: http://localhost:8080/manager/text/list -> [Help 1]

[1] http://www.onehippo.org/library/development/run-and-develop-with-cargo.html