Fix exec icon location and bring it into XDG compliance

diff --git a/kaffeine/src/player-parts/xine-part/xineconfig.cpp b/kaffeine/src/player-parts/xine-part/xineconfig.cpp
index 0ec9f38..33436a7 100644
--- a/kaffeine/src/player-parts/xine-part/xineconfig.cpp
+++ b/kaffeine/src/player-parts/xine-part/xineconfig.cpp
@@ -268,7 +268,7 @@
 		else if (*it == "osd")
 			icon = "application-x-font-snf";
 		else if (*it == "engine")
-			icon = "exec";
+			icon = "application-x-executable";
 		else
 			icon = "edit";