Don't report lints for comments after closing curly brace

The `EmptyLineBetweenBlocks` linter would incorrectly report lints for
code with comments immediately following the closing curly brace, e.g.

    p {
      ...
    } // A comment

Fix this by checking specifically for the case when a `CommentNode` is
the next node and ignore it.

Change-Id: I242443cde3bb0b0bbd9423d6d52a9049ea7a05f2
Reviewed-on: http://gerrit.causes.com/42988
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>