Change UserProfile.enter_sends to default to False.

Adds a database migration.

zerver/migrations/0048_enter_sends_default_to_false.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.4 on 2016-12-29 02:18
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('zerver', '0047_realm_add_emoji_by_admins_only'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='userprofile',
+            name='enter_sends',
+            field=models.NullBooleanField(default=False),
+        ),
+    ]