Bump jetty-server in /remote-music-player

Bumps [jetty-server](https://github.com/eclipse/jetty.project) from 9.4.35.v20201120 to 9.4.38.v20210224.
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.35.v20201120...jetty-9.4.38.v20210224)

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

remote-music-player/pom.xml

@@ -45,7 +45,7 @@
     <dependency>
       <groupId>org.eclipse.jetty</groupId>
       <artifactId>jetty-server</artifactId>
-      <version>9.4.35.v20201120</version>
+      <version>9.4.38.v20210224</version>
     </dependency>
     <dependency>
       <groupId>org.java-websocket</groupId>