Add missing migration file

InvenTree/plugin/migrations/0003_pluginsetting.py

@@ -0,0 +1,26 @@
+# Generated by Django 3.2.10 on 2022-01-01 10:52
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('plugin', '0002_alter_pluginconfig_options'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='PluginSetting',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('key', models.CharField(help_text='Settings key (must be unique - case insensitive', max_length=50)),
+                ('value', models.CharField(blank=True, help_text='Settings value', max_length=200)),
+                ('plugin', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='settings', to='plugin.pluginconfig', verbose_name='Plugin')),
+            ],
+            options={
+                'unique_together': {('plugin', 'key')},
+            },
+        ),
+    ]