doc(k8s): removed unnecessary configurations.

[gxthrj]

What this PR does / why we need it:

1.make config.yaml from the latest version
2.remove some config not necessary

Pre-submission checklist:

• Did you explain what problem does this PR solve? Or what new features have been added?
• Have you added corresponding test cases?
• Have you modified the corresponding document?
• Is this PR backward compatible?

[membphis]

@gxthrj please take a look at the output of Github Action:

https://github.com/apache/incubator-apisix/pull/1891/checks?check_run_id=913422137#step:6:61

Scan detected 2 error(s) in 2 file(s):
Reading configuration file [.travis/ASF-Release.cfg]...
Scanning files starting at [./]...
Scan detected 2 error(s) in 2 file(s):
  [./kubernetes/config.sh]:
       1: file does not include required license header.
  [./kubernetes/deployment.yaml]:
     113: file does not end with EOL.

[gxthrj]

@gxthrj please take a look at the output of Github Action:

https://github.com/apache/incubator-apisix/pull/1891/checks?check_run_id=913422137#step:6:61

Scan detected 2 error(s) in 2 file(s):
Reading configuration file [.travis/ASF-Release.cfg]...
Scanning files starting at [./]...
Scan detected 2 error(s) in 2 file(s):
  [./kubernetes/config.sh]:
       1: file does not include required license header.
  [./kubernetes/deployment.yaml]:
     113: file does not end with EOL.

done