db upgrade: stop containers only after exporting

we cannot export if the containers were nuked in the platform logic.
for this reason, move the removal near the place where they get started.

src/mail.js

@@ -630,7 +630,10 @@ function configureMail(mailFqdn, mailDomain, callback) {
         if (!safe.child_process.execSync(`cp ${bundle.certFilePath} ${mailCertFilePath}`)) return callback(new BoxError(BoxError.FS_ERROR, 'Could not create cert file:' + safe.error.message));
         if (!safe.child_process.execSync(`cp ${bundle.keyFilePath} ${mailKeyFilePath}`)) return callback(new BoxError(BoxError.FS_ERROR, 'Could not create key file:' + safe.error.message));
 
-        shell.exec('startMail', 'docker rm -f mail || true', function (error) {
+        async.series([
+            shell.exec.bind(null, 'stopMail', 'docker stop mail || true'),
+            shell.exec.bind(null, 'removeMail', 'docker rm -f mail || true'),
+        ], function (error) {
             if (error) return callback(error);
 
             createMailConfig(mailFqdn, mailDomain, function (error, allowInbound) {