Properly escape the dot character in regexp (#4608)

A follow-up to #4604: the dot in the regexp was not escaped as intended. By default `*` matches greedily, so the results are the same, but the new regexp should be more clear. Sorry for the mistake.

server/utils.js

@@ -3,7 +3,7 @@ import { readdirSync, existsSync } from 'fs'
 
 export function getChunkNameFromFilename (filename, dev) {
   if (dev) {
-    return filename.replace(/.[^.]*$/, '')
+    return filename.replace(/\.[^.]*$/, '')
   }
   return filename.replace(/-[^-]*$/, '')
 }