build: discard npm version upgrade karma anyway

afterbuild.js

@@ -4,16 +4,22 @@ const cp = require('child_process')
 
 const karmaPath = path.join(__dirname, 'node_modules', 'karma')
 
+function upgradeKarma () {
+  console.log(`you are using socket.io version under 2.x, upgrading now...`)
+  cp.execSync('npm install [email protected]', {
+    cwd: karmaPath
+  })
+}
+
 try {
   const { version } = JSON.parse(
     fs.readFileSync(
       path.join(karmaPath, 'node_modules', 'socket.io', 'package.json')
     )
   )
   if (parseInt(version, 10) < 2) {
-    console.log(`you are using karma version under 2.x, upgrading now...`)
-    cp.execSync('npm install [email protected]', {
-      cwd: karmaPath
-    })
+    upgradeKarma()
   }
-} catch (e) {}
+} catch (e) {
+  upgradeKarma()
+}