make TLS config params can be setup in the file

[yyb196]

Signed-off-by: Frank Yang yyb196@gmail.com

Ⅰ. Describe what this PR did

make TLS config params can be setup in the config file which introduce by falg --config-file

Ⅱ. Does this pull request fix one issue?

Ⅲ. Describe how you did it

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

@Ace-Tang

[codecov-io]

Codecov Report

Merging #1126 into master will decrease coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1126      +/-   ##
==========================================
- Coverage   15.74%   15.74%   -0.01%     
==========================================
  Files         172      172              
  Lines        9648     9630      -18     
==========================================
- Hits         1519     1516       -3     
+ Misses       8020     8005      -15     
  Partials      109      109

Impacted Files	Coverage Δ
client/client.go	30% <0%> (-9.4%)	⬇️
pkg/kernel/kernel.go	72.72% <0%> (-7.28%)	⬇️
cli/cli.go	0% <0%> (ø)	⬆️
ctrd/client.go	0% <0%> (ø)	⬆️

[Ace-Tang]

LGTM.

Since encoding/json cannot do the trick with ">some>deep>childnode" like encoding/xml can do. Nested structs is the way to go.

I want to re-implement daemon config merge function.