Remove early return in upkeep() in case sys.stdout is replaced.

We don't want flushing to be entirely skipped just because
of that.

src/world.py

@@ -154,9 +154,9 @@ def upkeep():
         if not hasattr(sys.stdout, 'getvalue'):
             # Stupid twisted sometimes replaces our stdout with theirs, because
             # "The Twisted Way Is The Right Way" (ha!).  So we're stuck simply
-            # returning.
+            # skipping the checks
             log.warning('Expected cStringIO as stdout, got %r.', sys.stdout)
-            return
+        else:
             s = sys.stdout.getvalue()
             if s:
                 log.warning('Printed to stdout after daemonization: %s', s)