max custom field name should be longer

smash/web/migrations/0192_auto_20201207_0956.py

+# Generated by Django 3.1.3 on 2020-12-07 09:56
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('web', '0191_auto_20201201_1033'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='customstudysubjectfield',
+            name='name',
+            field=models.CharField(max_length=64),
+        ),
+    ]

smash/web/models/custom_data/custom_study_subject_field.py

@@ -6,7 +6,7 @@ from web.models.constants import CUSTOM_FIELD_TYPE
 
 
 class CustomStudySubjectField(models.Model):
-    name = models.CharField(max_length=20, null=False, blank=False)
+    name = models.CharField(max_length=64, null=False, blank=False)
     type = models.CharField(max_length=20, choices=CUSTOM_FIELD_TYPE, null=False, blank=False)
 
     possible_values = models.CharField(max_length=1024, null=True, blank=True, default='')