Use IcedTea for VUE, not Oracle JRE

pkgs/top-level/all-packages.nix

···
   vorbisTools = callPackage ../applications/audio/vorbis-tools { };
 
   vue = callPackage ../applications/misc/vue {
-    jre = oraclejre;
+    jre = icedtea7_jre;
   };
 
   vwm = callPackage ../applications/window-managers/vwm { };