Fixed #16436 -- Oracle defer_regress test failure

Oracle doesn't like grouping by TextField, so use CharFields instead in
models.

tests/defer_regress/models.py

@@ -64,10 +64,10 @@ class ItemAndSimpleItem(models.Model):
     simple = models.ForeignKey(SimpleItem)
 
 class Profile(models.Model):
-    profile1 = models.TextField(default='profile1')
+    profile1 = models.CharField(max_length=1000, default='profile1')
 
 class Location(models.Model):
-    location1 = models.TextField(default='location1')
+    location1 = models.CharField(max_length=1000, default='location1')
 
 class Item(models.Model):
     pass
@@ -77,7 +77,7 @@ class Request(models.Model):
     location = models.ForeignKey(Location)
     items = models.ManyToManyField(Item)
 
-    request1 = models.TextField(default='request1')
-    request2 = models.TextField(default='request2')
-    request3 = models.TextField(default='request3')
-    request4 = models.TextField(default='request4')
+    request1 = models.CharField(default='request1', max_length=1000)
+    request2 = models.CharField(default='request2', max_length=1000)
+    request3 = models.CharField(default='request3', max_length=1000)
+    request4 = models.CharField(default='request4', max_length=1000)