DebugSQLTextTestResult crashes when database error is raised in setUpTestData().

[Mariusz Felisiak]

Running ./runtests.py postgres_tests.test_array --debug-sql with attached diff crashes:

./runtests.py postgres_tests.test_array --debug-sql
Testing against Django installed in '/django/django' with up to 4 processes
Creating test database for alias 'default'...
Got an error creating the test database: database "test_djangotest" already exists

Type 'yes' if you would like to try deleting the test database 'test_djangotest', or 'no' to cancel: yes
Destroying old test database for alias 'default'...
Cloning test database for alias 'default'...
Cloning test database for alias 'default'...
Cloning test database for alias 'default'...
Destroying old test database for alias 'default'...
Cloning test database for alias 'default'...
Destroying old test database for alias 'default'...
System check identified no issues (0 silenced).
EDestroying test database for alias 'default'...
Destroying test database for alias 'default'...
Destroying test database for alias 'default'...
Traceback (most recent call last):
  File "./runtests.py", line 589, in <module>
    options.timing,
  File "./runtests.py", line 320, in django_tests
    extra_tests=extra_tests,
  File "/django/django/test/runner.py", line 721, in run_tests
    result = self.run_suite(suite)
  File "/django/django/test/runner.py", line 662, in run_suite
    return runner.run(suite)
  File "/usr/lib/python3.6/unittest/runner.py", line 176, in run
    test(result)
  File "/usr/lib/python3.6/unittest/suite.py", line 84, in __call__
    return self.run(*args, **kwds)
  File "/django/django/test/runner.py", line 418, in run
    handler(test, *args)
  File "/django/django/test/runner.py", line 59, in addError
    self.debug_sql_stream.seek(0)
AttributeError: 'DebugSQLTextTestResult' object has no attribute 'debug_sql_stream'