Time & date Windows encoding

On Windows, the encoding was always the default windows encoding and
didn't change when you use a language in BM that required a different
encoding. This affected mainly date & time in the received column and
the startup info on the network status tab.

src/bitmessageqt/__init__.py

@@ -110,6 +110,8 @@ def change_translation(locale):
         pythonlocale.setlocale(pythonlocale.LC_ALL, lang)
         if 'win32' not in sys.platform and 'win64' not in sys.platform:
             l10n.encoding = pythonlocale.nl_langinfo(pythonlocale.CODESET)
+        else:
+            l10n.encoding = pythonlocale.getlocale()[1]
     except:
         logger.error("Failed to set locale to %s", lang, exc_info=True)