[downloader/dash] Reorder imports

youtube_dl/downloader/dash.py

@@ -1,9 +1,10 @@
 from __future__ import unicode_literals
-from .common import FileDownloader
-from ..compat import compat_urllib_request
 
 import re
 
+from .common import FileDownloader
+from ..compat import compat_urllib_request
+
 
 class DashSegmentsFD(FileDownloader):
     """