Added ')' to jdk unbounded range for Maven 2.X

I was trying to use the maven plugin in my project, and was getting the the following error:

    [ERROR] BUILD ERROR
    [INFO] ------------------------------------------------------------------------
    [INFO] Error building POM (may not be this project's POM).


    Project ID: org.jsonschema2pojo:jsonschema2pojo

    Reason: Invalid JDK version in profile 'doclint-java8-disable': Unbounded range: [1.8, for project org.jsonschema2pojo:jsonschema2pojo

Investigating, I found that Maven 2.x has a problem parsing unbound versions without ')'. This pull request adds the same to the jdk version range.