Icecast SD: add Radio in the title

(cherry picked from commit d16dfb39)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

share/lua/sd/icecast.lua

@@ -22,7 +22,7 @@
 require "simplexml"
 
 function descriptor()
-    return { title="Icecast Directory" }
+    return { title="Icecast Radio Directory" }
 end
 
 function main()