better approach for cgi upload disabling

Make it a config setting, this way subtle load order issues don't come into
play. (As much?)

IkiWiki.pm

@@ -88,6 +88,7 @@ sub defaultconfig () { #{{{
 	account_creation_password => "",
 	prefix_directives => 0,
 	hardlink => 0,
+	cgi_disable_uploads => 1,
 } #}}}
 
 sub checkconfig () { #{{{

IkiWiki/CGI.pm

@@ -6,8 +6,6 @@ use IkiWiki;
 use IkiWiki::UserInfo;
 use open qw{:utf8 :std};
 use Encode;
-use CGI;
-$CGI::DISABLE_UPLOADS=1;
 
 package IkiWiki;
 
@@ -668,6 +666,10 @@ sub cgi (;$$) { #{{{
 	my $q=shift;
 	my $session=shift;
 
+	eval q{use CGI};
+	error($@) if $@;
+	$CGI::DISABLE_UPLOADS=$config{cgi_disable_uploads};
+
 	if (! $q) {
 		binmode(STDIN);
 		$q=CGI->new;

IkiWiki/Plugin/attachment.pm

@@ -4,18 +4,21 @@ package IkiWiki::Plugin::attachment;
 use warnings;
 use strict;
 use IkiWiki 2.00;
-use CGI;
-$CGI::DISABLE_UPLOADS=0;
 
 # TODO move to admin prefs
 $config{valid_attachments}="(*.mp3 and maxsize(15mb)) or (!ispage() and maxsize(50kb))";
 
 sub import { #{{{
+	hook(type => "checkconfig", id => "attachment", call => \&checkconfig);
 	hook(type => "formbuilder_setup", id => "attachment", call => \&formbuilder_setup);
 	hook(type => "formbuilder", id => "attachment", call => \&formbuilder);
 } # }}}
 
-sub formbuilder_setup { #{{{
+sub checkconfig () { #{{{
+	$config{cgi_disable_uploads}=0;
+} #}}}
+
+sub formbuilder_setup (@) { #{{{
 	my %params=@_;
 	my $form=$params{form};