do not re-generate DATABASE_ERROR

src/docker.js

@@ -235,7 +235,7 @@ function createSubcontainer(app, name, cmd, options, callback) {
     if (!isAppContainer) memoryLimit *= 2;
 
     addons.getEnvironment(app, function (error, addonEnv) {
-        if (error) return callback(new BoxError(BoxError.DATABASE_ERROR, 'Error getting addon environment : ' + error.message));
+        if (error) return callback(error);
 
         // do no set hostname of containers to location as it might conflict with addons names. for example, an app installed in mail
         // location may not reach mail container anymore by DNS. We cannot set hostname to fqdn either as that sets up the dns