munin_events: fix plugin having too much output

in 56cd2c926c "&> /dev/null" was converted
to posix in an invalid way, should have been ">/dev/null 2>&1"

plugins/munin/munin_events

@@ -87,7 +87,7 @@ values() {
     do_value 'munin_error' 'ERROR'
     do_value 'munin_fatal' 'FATAL'
     # Set offset
-    "$logtail_bin" "$muninupdate" > /dev/null 1>&2
+    "$logtail_bin" "$muninupdate" >/dev/null 2>&1
     chmod 640 "${muninupdate}.offset"
 }