check for undefined owserver connection in Find

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@2750 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/FHEM/10_OWServer.pm

@@ -314,6 +314,7 @@ OWServer_Find($@)
   my ($hash,$slave)= @_;
   my $owserver= $hash->{fhem}{owserver};
 
+  return undef unless(defined($hash->{fhem}{owserver}));
   my @dir= split(",",$owserver->dir("/"));
   my $path= undef;
   for my $entry (@dir) {