Quit logging clipboard contents to the systemd journal. For cdown#49

I'm not sure if this issue happens all the time, or only when
/dev/stderr can't be read.

Perhaps in debug mode it would be better to not send this output
to /dev/null, since it might be helpful for diagnostics.

clipmenud

@@ -13,7 +13,7 @@ lock_file=$cache_dir/lock
 lock_timeout=2
 
 _xsel() {
-    timeout 1 xsel --logfile /dev/stderr "$@"
+    timeout 1 xsel --logfile /dev/stderr "$@" 2>/dev/null
 }
 
 get_first_line() {