pycurl FTBFS due to segfault in test suite

pycurl FTBFS in Raring:

https://launchpadlibrarian.net/135742128/buildlog_ubuntu-raring-amd64.pycurl_7.19.0-5ubuntu6_FAILEDTOBUILD.txt.gz

The problem is that the test suite runs test_internals.py, and this segfaults. This is easily reproducible outside the build environment using the following code:

$ python
>>> from pycurl import CurlMulti
>>> m = CurlMulti()
>>> del m
Segmentation fault (core dumped)

Tracing through with gdb, the problem appears that calling curl_multi_cleanup() on a CURLM* previously returned by curl_multi_init() is what crashes. The cleanup is called from util_multi_close() in pycurl.c via do_multi_dealloc() but afaict, the CURLM* handle is valid. Or at least, it's unchanged from what curl_multi_init() returns. The above code is taken directly from test_internals.py with the extraneous stuff boiled out.

# remove an invalid but closed handle
if 1:
    m = CurlMulti()
    c = Curl()
    c.close()
    m.remove_handle(c)
    del m, c

'c' isn't needed to reproduce the crash.