Ignore crypt deprication warning

I know it's going away. It's guarded by a try block. No need to keep
reporting it.

Author: rouilj

roundup/password.py

@@ -26,8 +26,12 @@
 from roundup.anypy.strings import us2s, b2s, s2b
 import roundup.anypy.random_ as random_
 
+import warnings
+
 try:
-    import crypt
+    with warnings.catch_warnings():
+        warnings.filterwarnings("ignore", category=DeprecationWarning)
+        import crypt
 except ImportError:
     crypt = None