Bump jetty-server from 9.2.12.v20150709 to 11.0.15

Bumps [jetty-server](https://github.com/eclipse/jetty.project) from 9.2.12.v20150709 to 11.0.15.
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](https://github.com/eclipse/jetty.project/compare/jetty-9.2.12.v20150709...jetty-11.0.15)

---
updated-dependencies:
- dependency-name: org.eclipse.jetty:jetty-server
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/pom.xml b/pom.xml
index ebc07e2..d016f96 100644
--- a/pom.xml
+++ b/pom.xml
@@ -484,7 +484,7 @@
         <node.version>v0.10.30</node.version>
         <node-for-v2.version>v4.4.2</node-for-v2.version>
         <slf4j.version>1.7.21</slf4j.version>
-        <jetty.version>9.2.12.v20150709</jetty.version>
+        <jetty.version>11.0.15</jetty.version>
         <jersey.version>1.19</jersey.version>
         <tinkerpop.version>2.6.0</tinkerpop.version>
         <titan.version>0.5.4</titan.version>