fix sampy.py SSL issue that prevents sherpa from connecting via SAMP

[jbudynk]

The newer versions of conda have an updated SSL package that no longer has PROTOCOL_SSLv3 defined. sampy.py, which hasn't been developed in about 10 years, sets up an HTTPSConnection with ssl_version = ssl.PROTOCOL_SSLv3. This raises an AttributeError in sampy.py.

Original email of issue (from me):

Sherpa is started, but it can't connect to the SAMP hub due to an issue with the SSL package:

cat /data/scialg/staff/jbudynk/iris-issue/note.txt
/data/vao/staff/jbudynk/mojave-issue-sherpa-samp.traceback

(iris3.0) dudley:~ saoguest$ sherpa-samp
Traceback (most recent call last):
  File "/Users/saoguest/miniconda2/envs/iris3.0/bin/sherpa-samp", line 11, in <module>
    load_entry_point('sherpa-samp==2.1', 'console_scripts', 'sherpa-samp')()
  File "/Users/saoguest/miniconda2/envs/iris3.0/lib/python2.7/site-packages/pkg_resources/__init__.py", line 489, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/Users/saoguest/miniconda2/envs/iris3.0/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2793, in load_entry_point
    return ep.load()
  File "/Users/saoguest/miniconda2/envs/iris3.0/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2411, in load
    return self.resolve()
  File "/Users/saoguest/miniconda2/envs/iris3.0/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2417, in resolve
    module = __import__(self.module_name, fromlist=['__name__'], level=0)
  File "build/bdist.macosx-10.7-x86_64/egg/sherpa_samp/mtypes.py", line 28, in <module>
  File "/Users/saoguest/miniconda2/envs/iris3.0/lib/python2.7/site-packages/sampy.py", line 914, in <module>
    class HTTPSConnection(httplib.HTTPConnection):
  File "/Users/saoguest/miniconda2/envs/iris3.0/lib/python2.7/site-packages/sampy.py", line 921, in HTTPSConnection
    ssl_version=ssl.PROTOCOL_SSLv3, strict=None):
AttributeError: 'module' object has no attribute 'PROTOCOL_SSLv3'

sampy imports the SSL library from iris/lib/python2.7/ssl.py. The 'PROTOCOL_SSLv3' variable is loaded from iris/lib/python2.7/lib-dynload/_ssl.so. I'm guessing that the variable PROTOCOL_SSLv3 defined in _ssl.so isn't read in correctly, thus the AttributeError in sampy.py.

I really don't know anything about SSL, but just to see if it would fix the issue -- If we switch the default protocol to 'PROTOCOL_SSLv23' in all the sampy.py methods, Sherpa connects to the SAMP hub, and I can compute fits in Iris again. iris/lib/python2.7/ssl.py defines "PROTOCOL_SSLv23 = PROTOCOL_TLS".

And @olaurino 's response:

We are using very old (like ancient) packages. Sampy hasn't been actively developed for almost a decade, it was already obsolete when we started using it, but we couldn't switch to astropy.samp. If you think you have a fix, try fixing sampy and creating a new conda package. An alternative would be to find which past version of python 2.7 fixes the problem.

If you go the conda way, you can start from here:
https://github.com/olaurino/conda-recipes

Download the source code from the URL in the sampy/meta.yaml file, make the file point to the location where you unpacked it and fixed it (file:///etc), increase the build number in meta.yaml, cd to that folder, and then do conda build .

Install the new package with conda install --use-local sampy, and see if it works.