settings: don't set DEFAULT_FROM_EMAIL by default

The default value of the From: header for outgoing is almost certainly
better than "no-reply@example.com".

coin/settings.py

@@ -215,7 +215,7 @@ TEST_RUNNER = 'django.test.runner.DiscoverRunner'
 GRAPHITE_SERVER = "http://localhost"
 
 # Configuration for outgoing emails
-DEFAULT_FROM_EMAIL = "no-reply@example.com"
+#DEFAULT_FROM_EMAIL = "coin@example.com"
 #EMAIL_USE_TLS = True
 #EMAIL_HOST = "smtp.chezmoi.tld"