[ZopeTestCase] failure of testPackageAsProduct on 2.10 branch

[Andreas Jung]

zopectl test -s Testing

on the 2.10 branch fails:

File "/develop/sandboxes/Zope-2.10/Zope/lib/python/Testing/ZopeTestCase/zopedoctest/testPackageAsProduct.py", line 83, in Testing.ZopeTestCase.zopedoctest.testPackageAsProduct.testInstallPackage
Failed example:
    ZopeTestCase.installPackage('testpackage', quiet=True)
Exception raised:
    Traceback (most recent call last):
      File "/develop/sandboxes/Zope-2.10/Zope/lib/python/zope/testing/doctest.py", line 1348, in __run
        compileflags, 1) in test.globs
      File "<doctest Testing.ZopeTestCase.zopedoctest.testPackageAsProduct.testInstallPackage[12]>", line 1, in ?
        ZopeTestCase.installPackage('testpackage', quiet=True)
      File "/develop/sandboxes/Zope-2.10/Zope/lib/python/Testing/ZopeTestCase/ZopeLite.py", line 177, in installPackage
        for module, init_func in Products._packages_to_initialize:
    AttributeError: 'module' object has no attribute '_packages_to_initialize'

[Stefan H. Holek (stefanholek)]

Fixed breakage caused by backport of #2358.