idp_oidc: change type of OIDCCode.redirect_uri (#44589)

To accept URL of any length.

src/authentic2_idp_oidc/migrations/0013_auto_20200630_1007.py

@@ -0,0 +1,19 @@
+# Generated by Django 2.2.13 on 2020-06-30 08:07
+
+import django.core.validators
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('authentic2_idp_oidc', '0012_auto_20200122_2258'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='oidccode',
+            name='redirect_uri',
+            field=models.TextField(validators=[django.core.validators.URLValidator()], verbose_name='redirect URI'),
+        ),
+    ]

src/authentic2_idp_oidc/models.py

@@ -299,8 +299,9 @@ class OIDCCode(models.Model):
     nonce = models.TextField(
         null=True,
         verbose_name=_('nonce'))
-    redirect_uri = models.URLField(
-        verbose_name=_('redirect URI'))
+    redirect_uri = models.TextField(
+        verbose_name=_('redirect URI'),
+        validators=[URLValidator()])
     session_key = models.CharField(
         verbose_name=_('session key'),
         max_length=128)