issue #186: core: remove long-forgotten hack.

This is likely to break something, it was definitely needed at some
point, but I never put much effort into figuring out why. Meanwhile,
Python appears to make find_module('ansible.module_utils.facts.')
requests in some circumstances, which causes us to indicate the module
exists while this hack exists.

So remove it, and let's see what breaks.

mitogen/core.py

@@ -623,7 +623,6 @@ class Importer(object):
             return None
 
         _tls.running = True
-        fullname = fullname.rstrip('.')
         try:
             pkgname, dot, _ = fullname.rpartition('.')
             _v and LOG.debug('%r.find_module(%r)', self, fullname)