Issue $413 patcher diverts subprocess exceptions instead of keeping c…

…lass identity

reset new reimport module in sys.modules.

eventlet#413

eventlet/green/subprocess.py

@@ -16,7 +16,7 @@
     from eventlet.green import selectors
     to_patch.append(('selectors', selectors))
 
-patcher.inject('subprocess', globals(), *to_patch)
+sys.modules['subprocess'] = patcher.inject('subprocess', globals(), *to_patch)
 subprocess_orig = patcher.original("subprocess")
 mswindows = sys.platform == "win32"