Update django.po

Corrected the translation to Russian. Now the emails from the app will look better.

Author: savelmtr

django_messages/locale/ru/LC_MESSAGES/django.po

@@ -224,7 +224,7 @@ msgid ""
 "you received a private message from %(sender)s with\n"
 "the following contents:"
 msgstr ""
-"Hallo %(recipient)s,\n"
+"Приветствуем, %(recipient)s!\n"
 "\n"
 "Вы получили сообщение от %(sender)s\n"
 "со следующим содержанием:"