[1.7.x] Prevented a crash in the cursor wrappers on Oracle.

Fixed #22483 (again).

Backport of 0f85103e from master

django/db/backends/utils.py

@@ -36,8 +36,12 @@ class CursorWrapper(object):
 
     def __exit__(self, type, value, traceback):
         # Ticket #17671 - Close instead of passing thru to avoid backend
-        # specific behavior.
-        self.close()
+        # specific behavior. Catch errors liberally because errors in cleanup
+        # code aren't useful.
+        try:
+            self.close()
+        except self.db.Database.Error:
+            pass
 
     # The following methods cannot be implemented in __getattr__, because the
     # code must run when the method is invoked, not just when it is accessed.