[xhamster] Remove md5sums from tests

We're now checking that the file is sufficiently large by default, and they seem to reencode the videos from time to time.

youtube_dl/extractor/xhamster.py

@@ -18,7 +18,6 @@ class XHamsterIE(InfoExtractor):
     _TESTS = [
         {
             'url': 'http://xhamster.com/movies/1509445/femaleagent_shy_beauty_takes_the_bait.html',
-            'md5': '8281348b8d3c53d39fffb377d24eac4e',
             'info_dict': {
                 'id': '1509445',
                 'ext': 'mp4',
@@ -31,7 +30,6 @@ class XHamsterIE(InfoExtractor):
         },
         {
             'url': 'http://xhamster.com/movies/2221348/britney_spears_sexy_booty.html?hd',
-            'md5': '4cbd8d56708ecb4fb4124c23e4acb81a',
             'info_dict': {
                 'id': '2221348',
                 'ext': 'mp4',