bitbake: daemonize/prserv/tests/fetch: Convert file() -> open()

Use python3 compatible functions.

(Bitbake rev: e6a0296ba29c3fbc8417d1df7a01d50562668a41)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/tests/fetch.py

@@ -450,7 +450,7 @@ class MirrorUriTest(FetcherTest):
 class FetcherLocalTest(FetcherTest):
     def setUp(self):
         def touch(fn):
-            with file(fn, 'a'):
+            with open(fn, 'a'):
                 os.utime(fn, None)
 
         super(FetcherLocalTest, self).setUp()