Bump jetty-server from 9.4.28.v20200408 to 9.4.30.v20200611 in /embedded

Bumps [jetty-server](https://github.com/eclipse/jetty.project) from 9.4.28.v20200408 to 9.4.30.v20200611.
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](https://github.com/eclipse/jetty.project/compare/jetty-9.4.28.v20200408...jetty-9.4.30.v20200611)

Signed-off-by: dependabot[bot] <support@github.com>

embedded/pom.xml

@@ -53,7 +53,7 @@
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-server</artifactId>
-      <version>9.4.28.v20200408</version>
+      <version>9.4.30.v20200611</version>
     </dependency>
     <dependency>
       <groupId>org.eclipse.jetty</groupId>