Revert "Labels should get their information from the render function of the records."

This reverts commit 65c87386c1.

gluon/validators.py

@@ -578,9 +578,9 @@ class IS_IN_DB(Validator):
             records = self.dbset(table).select(table.ALL, **dd)
         self.theset = [str(r[self.kfield]) for r in records]
         if isinstance(self.label, str):
-            self.labels = [self.label % r for r in records.render()]
+            self.labels = [self.label % r for r in records]
         else:
-            self.labels = [self.label(r) for r in records.render]
+            self.labels = [self.label(r) for r in records]
 
     def options(self, zero=True):
         self.build_set()