Revert "added setting of ansible_ssh_user to current user as backwards compatibilty issue"

scope was wrong, this var should not be 'reset' here.

This reverts commit c271c0eb04.

lib/ansible/playbook/play_context.py

@@ -26,9 +26,6 @@ import random
 import re
 import string
 
-from pwd import getpwuid
-from os import geteuid
-
 from ansible.compat.six import iteritems, string_types
 from ansible import constants as C
 from ansible.errors import AnsibleError
@@ -482,7 +479,3 @@ class PlayContext(Base):
                 for prop, varnames in MAGIC_VARIABLE_MAPPING.items():
                     if special_var in varnames:
                         variables[special_var] = getattr(self, prop)
-
-        # for backwards compat
-        if variables['ansible_ssh_user'] is None:
-            variables['ansible_ssh_user'] = getpwuid(geteuid())[0]