Fix server postbuild script

scripts/server.postbuild.ts

@@ -8,16 +8,23 @@ import { join } from 'path'
 */
 
 const cwd = process.cwd()
-const originalDistPath = join(cwd, 'dist_server')
-const tempSrcPath = join(cwd, 'src_temp')
+const distPath = join(cwd, 'dist_server')
+const distSrcPath = join(distPath, 'src')
+const tempDistSrcPath = join(cwd, 'src_temp')
+
+// there are no custom modules in `config/modules`
+if (!fs.existsSync(join(distPath, 'config'))) {
+  // delete `dist_server/src` if present (previous build output)
+  if (fs.existsSync(distSrcPath)) {
+    fs.rmSync(distSrcPath, { recursive: true })
+  }
 
-if (!fs.existsSync(join(originalDistPath, 'src'))) {
   // rename `dist_server` to `src_temp`
-  fs.renameSync(originalDistPath, tempSrcPath)
+  fs.renameSync(distPath, tempDistSrcPath)
 
   // create new empty folder `dist_server`
-  fs.mkdirSync(originalDistPath)
+  fs.mkdirSync(distPath)
 
   // rename `src_temp` to `dist_server/src`
-  fs.renameSync(tempSrcPath, join(originalDistPath, 'src'))
+  fs.renameSync(tempDistSrcPath, join(distPath, 'src'))
 }