Update jackson and jetty
Just bug fixes.
<!-- can't upgrade jersey past 2.25 until we move to java 8 -->
<jersey.version>2.25</jersey.version>
<!-- can't upgrade jetty past 9.2 until we move to java 8 -->
- <jetty.version>9.2.22.v20170606</jetty.version>
- <jackson.version>2.9.1</jackson.version>
+ <jetty.version>9.2.24.v20180105</jetty.version>
+ <jackson.version>2.9.4</jackson.version>
</properties>
<repositories>
