added a line for adding allowPublicSignup config variable to theme

Author: danielfang97

lib/views/admin/theme.js

@@ -69,6 +69,7 @@ function form (req, res) {
     altHome: config.get('altHome'),
     showModuleInteractions: config.get('showModuleInteractions'),
     removePublicEnabled: config.get('removePublicEnabled'),
+    allowPublicSignup: config.get('allowPublicSignup'),
     requireLogin: config.get('requireLogin'),
     currentTheme: currentTheme,
     themeParameters: themeParameters