I had a similar problem. I was working on a project where I did not control the web.xml configuration file, so I could not use the changes suggested about altering the version. Of course the project was not using JSF so this was especially annoying for me.
I found that there is a really simple fix. Go to Preferences > Maven > Java EE Itegration and uncheck the "JSF Configurator" box.
I did this in a fresh workspace before importing the project again, but it may work equally as well on an existing project ... not sure.