cmd.run state doesn't print stdout's last character when stateful=True.

Description of Issue

When executing the state cmd.run on a minion with stateful set to True and the command returns key/value pairs (not JSON), then the last character printed in the Changes: section is omitted.

Setup

Ran on debian10 with 2019.2.3+ds-1 salt package, but I've verified it in various previous salt versions (eg. 2018.3.1 and 2018.3.2) on various systems (eg. debian9 and SmartOS 18.4, 19.4, 17.2).

Steps to Reproduce Issue

Create the following sls file in your file-roots (let's call it testit.sls):

test output1:
  cmd.run:
    - name: echo changed=True lala=lolo lili=lele

test output2:
  cmd.run:
    - name: echo changed=True lala=lolo lili=lele
    - stateful: True

and then run it. The output you'll get will be something like:

# salt 'testmachine' state.apply testit
testmachine:
----------
          ID: test output1
    Function: cmd.run
        Name: echo changed=True lala=lolo lili=lele
      Result: True
     Comment: Command "echo changed=True lala=lolo lili=lele" run
     Started: 13:37:29.594337
    Duration: 83.475 ms
     Changes:   
              ----------
              pid:
                  20544
              retcode:
                  0
              stderr:
              stdout:
                  changed=True lala=lolo lili=lele
----------
          ID: test output2
    Function: cmd.run
        Name: echo changed=True lala=lolo lili=lele
      Result: True
     Comment: 
     Started: 13:37:29.678552
    Duration: 77.335 ms
     Changes:   
              ----------
              changed:
                  True
              lala:
                  lolo
              lili:
                  lele
              pid:
                  20545
              retcode:
                  0
              stderr:
              stdout:
                  changed=True lala=lolo lili=lel

Summary for testmachine
------------
Succeeded: 2 (changed=2)
Failed:    0
------------
Total states run:     2
Total run time: 160.810 ms

where one can see that the final e is missing from the output2 (where stateful is set to True).

Versions Report

           Salt: 2019.2.3
 
Dependency Versions:
           cffi: Not Installed
       cherrypy: unknown
       dateutil: 2.7.3
      docker-py: Not Installed
          gitdb: 2.0.5
      gitpython: 2.1.11
          ioflo: Not Installed
         Jinja2: 2.10
        libgit2: Not Installed
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.5.6
   mysql-python: Not Installed
      pycparser: Not Installed
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 3.7.3 (default, Apr  3 2019, 05:39:12)
   python-gnupg: Not Installed
         PyYAML: 3.13
          PyZMQ: 17.1.2
           RAET: Not Installed
          smmap: 2.0.5
        timelib: Not Installed
        Tornado: 4.5.3
            ZMQ: 4.3.1
 
System Versions:
           dist: debian 10.2 
         locale: UTF-8
        machine: x86_64
        release: 4.19.0-6-cloud-amd64
         system: Linux
        version: debian 10.2 

Reproduce the issue with the provided testit.sls file by running salt 'testmachine' state.apply testit on a stateful cmd.run. Trace the cmd.run stateful output handling, then verify that the final stdout character is preserved and add a regression test covering non-JSON key/value output.