sftp: require admin by default (breaking change)

migrations/20201204081504-settings-sftp-requireAdmin.js

@@ -4,11 +4,11 @@ exports.up = function(db, callback) {
     db.all('SELECT * FROM settings WHERE name=?', ['platform_config'], function (error, results) {
         let value;
         if (error || results.length === 0) {
-            value = { sftp: { requireAdmin: true } }; // new installations
+            value = { sftp: { requireAdmin: true } };
         } else {
             value = JSON.parse(results[0].value);
             if (!value.sftp) value.sftp = {};
-            value.sftp.requireAdmin = false; // existing installation, backward compat
+            value.sftp.requireAdmin = true;
         }
 
         db.runSql('UPDATE settings SET value=? WHERE name=?', [ JSON.stringify(value), 'platform_config' ], callback);