Fix typo. (What I get for trying to fix bugs at home and running conversions

at work....)

Doc/perl/python.perl

@@ -671,7 +671,7 @@ sub do_env_memberdesc{
     $class = $THIS_CLASS
         unless $class;
     $extra = " ($class_name attribute)"
-        if (!($class eq));
+        if (!($class eq ''));
     my $idx = make_str_index_entry($3, "<tt>$member</tt>$extra");
     $idx =~ s/ \(.*\)//;
     $idx =~ s/\(\)//;