Better fix for Python 2

The multiprocessing module in Python 2 does not support
different contexts, so just fall back to the module
itself.

modules/multifit/pyext/src/fit_fft.py

@@ -24,13 +24,16 @@
 
 
 def _get_context():
-    # Use 'forkserver' rather than 'fork' start method if we can; 'fork' does
-    # not work well with multithreaded processes or CUDA
-    if (hasattr(multiprocessing, 'get_all_start_methods')
-            and 'forkserver' in multiprocessing.get_all_start_methods()):
-        return multiprocessing.get_context('forkserver')
+    if hasattr(multiprocessing, 'get_context'):
+        # Use 'forkserver' rather than 'fork' start method if we can;
+        # 'fork' does not work well with multithreaded processes or CUDA
+        if 'forkserver' in multiprocessing.get_all_start_methods():
+            return multiprocessing.get_context('forkserver')
+        else:
+            return multiprocessing.get_context()
     else:
-        return multiprocessing.get_context()
+        # For Python < 3.4, just use the original module
+        return multiprocessing
 
 
 class Fitter(object):