file.managed chmod failed if file attrs has already been set.

Description of Issue/Question

File chmod failed if attrs has already been set.
We should remove attrs --do chmod -- add old attrs back to avoid chmod failure.

Setup

(Please provide relevant configs and/or SLS files (Be sure to remove sensitive info).)

Steps to Reproduce Issue

(Include debug logs if possible and relevant.)

File:

## file mode is 002 and has a(appendonly) attr. failed to change mode to 222.
[root@localhost ~]# ls -alh /var/log/history/history.log
--------w- 1 root root 5.1K Oct 19 16:19 /var/log/history/history.log
[root@localhost ~]# lsattr /var/log/history/history.log
-----a-------e-- /var/log/history/history.log

Salt states:
history_log_file:
  file.managed:
    - name: /var/log/history/history.log
    - user: root
    - group: root
    - mode: 222
    - attrs: a

Output:
      ID: history_log_file
Function: file.managed
    Name: /var/log/history/history.log
  Result: False
 Comment: Failed to change mode to 0222
 Started: 16:19:06.438731
Duration: 1.575 ms
 Changes:

Versions Report

(Provided by running salt --versions-report. Please also mention any differences in master/minion versions.)

[root@localhost ~]# salt --versions-report
Salt Version:
           Salt: 2017.7.2

Dependency Versions:
           cffi: Not Installed
       cherrypy: unknown
       dateutil: Not Installed
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
          ioflo: Not Installed
         Jinja2: 2.8.1
        libgit2: Not Installed
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.4.6
   mysql-python: Not Installed
      pycparser: Not Installed
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 2.7.13 (default, Jul 12 2017, 17:32:34)
   python-gnupg: Not Installed
         PyYAML: 3.11
          PyZMQ: 14.5.0
           RAET: Not Installed
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.2.1
            ZMQ: 4.0.5

System Versions:
           dist: centos 6.9 Final
         locale: UTF-8
        machine: x86_64
        release: 2.6.32-431.23.3.el6.x86_64
         system: Linux
        version: CentOS 6.9 Final