Call "on_play" in background.

modules/liquidsoap/in_filesystem.liq

@@ -31,13 +31,13 @@ input_filesystem_1 = request.equeue(id="in_filesystem_1")
 #input_fs = cue_cut(mksafe(request.equeue(id="fs")))
 
 
-# Update Trackservice
+# Call engine core handler to "on_play" (e.g. to update track service)
 
 def do_meta_filesystem(meta) =
     filename = meta["filename"]
     # artist = meta["artist"]
     # title = meta["title"]
-    system('#{list.assoc(default="", "install_dir", ini)}/guru.py --on_play "#{filename}"')
+    system('#{list.assoc(default="", "install_dir", ini)}/guru.py --on_play "#{filename}" &')
 end
 
 input_filesystem_0 = on_metadata(id="in_filesystem_0", do_meta_filesystem, input_filesystem_0)