Update validator for supplier price break

InvenTree/part/migrations/0029_auto_20190518_1632.py

@@ -0,0 +1,19 @@
+# Generated by Django 2.2 on 2019-05-18 06:32
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('part', '0028_auto_20190518_1627'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='supplierpricebreak',
+            name='quantity',
+            field=models.PositiveIntegerField(validators=[django.core.validators.MinValueValidator(1)]),
+        ),
+    ]