32_TechemWZ.pm: fix for event-on fix

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@10662 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/FHEM/32_TechemWZ.pm

@@ -162,6 +162,7 @@ TechemWZ_Receive(@) {
   $ats = ReadingsTimestamp($hash->{NAME},"previous_period", "0");
   $ts = sprintf ("20%02d-%02d-%02d 00:00:00", $msg->{last}->{year}, $msg->{last}->{month}, $msg->{last}->{day});
   if ($ats ne $ts) {
+    my $i;
     readingsBeginUpdate($hash);
     $hash->{".updateTimestamp"} = $ts;
     $i = $#{ $hash->{CHANGED} };