In LJ::User->create_community, don't call $u->set_default_style in te…

…st environment.

This fixes a test-config related warning that printed during multiple tests, including t/content-filters.t:

"Can't call method "is_custom" on an undefined value at dw/cgi-bin/LJ/Customize.pm line 56."

The reason this was warning is because test environments don't set up styles.

cgi-bin/LJ/User/Account.pm

@@ -136,7 +136,7 @@ sub create_community {
     $u->set_prop("nonmember_posting", $opts{nonmember_posting}+0);
     $u->set_prop("moderated", $opts{moderated}+0);
     $u->set_prop("adult_content", $opts{journal_adult_settings}) if LJ::is_enabled( 'adult_content' );
-    $u->set_default_style;
+    $u->set_default_style unless $LJ::_T_CONFIG;
 
     my $admin = $opts{admin_userid} ?
         LJ::load_userid( $opts{admin_userid} ) :