Daemonize fix for Windows

- /dev/null isn't available on Windows so just close the console
sockets directly

src/bitmessagemain.py

@@ -351,12 +351,18 @@ class Main:
         shared.thisapp.lockPid = None # indicate we're the final child
         sys.stdout.flush()
         sys.stderr.flush()
+        try:
             si = file('/dev/null', 'r')
             so = file('/dev/null', 'a+')
             se = file('/dev/null', 'a+', 0)
             os.dup2(si.fileno(), sys.stdin.fileno())
             os.dup2(so.fileno(), sys.stdout.fileno())
             os.dup2(se.fileno(), sys.stderr.fileno())
+        # /dev/null not available
+        except IOError:
+            sys.stdin.close()
+            sys.stdout.close()
+            sys.stderr.close()
 
     def setSignalHandler(self):
         signal.signal(signal.SIGINT, helper_generic.signal_handler)