BR glibc-all-langpacks to fix a FTBFS and avoid skipped tests
    
    See https://fedoraproject.org/wiki/Changes/Remove_glibc-langpacks-all_from_buildroot
    
    The tests failed with:
    
    Some tests will be disabled: Test locale not supported
    (tried en_US.UTF-8, en_US.US-ASCII, en_US)
    ...
    ======================================================================
    ERROR: test_lookup_issue1813 (test.test_codecs.CodecsModuleTest)
    ----------------------------------------------------------------------
    Traceback (most recent call last):
      File "/builddir/build/BUILD/Python-2.7.15/Lib/locale.py", line 581, in setlocale
        return _setlocale(category, locale)
    Error: unsupported locale setting
    ----------------------------------------------------------------------
    ...
    ======================================================================
    ERROR: test_getsetlocale_issue1813 (test.test_locale.TestMiscellaneous)
    ----------------------------------------------------------------------
    Traceback (most recent call last):
      File "/builddir/build/BUILD/Python-2.7.15/Lib/locale.py", line 581, in setlocale
        return _setlocale(category, locale)
    Error: unsupported locale setting
    ======================================================================
    ERROR: test_setlocale_unicode (test.test_locale.TestMiscellaneous)
    ----------------------------------------------------------------------
    Traceback (most recent call last):
      File "/builddir/build/BUILD/Python-2.7.15/Lib/locale.py", line 581, in setlocale
        return _setlocale(category, locale)
    Error: unsupported locale setting
    ----------------------------------------------------------------------