fix(next-server): fix import path in test file

Author: nicksrandall

test/unit/next-server-compress.unit.test.js

@@ -2,7 +2,7 @@ import zlib from 'zlib'
 import http from 'http'
 import request from 'supertest'
 import crypto from 'crypto'
-import Compression from 'next/dist/server/compression'
+import Compression from 'next/next-server/server/compression'
 
 describe('next-server compression', () => {
   it('should skip HEAD', () => {