bugfix: setup hook in advance to avoid panic if no prestart hook setup before

[yyb196]

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

Ⅰ. Describe what this PR did

setup hook in advance to avoid panic if no prestart hook setup before this place

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

[allencloud]

Could we add an integration test to cover this? @yyb196 @wangforthinker

[codecov-io]

Codecov Report

Merging #1038 into master will not change coverage.
The diff coverage is 0%.

@@           Coverage Diff           @@
##           master    #1038   +/-   ##
=======================================
  Coverage   15.71%   15.71%           
=======================================
  Files         139      139           
  Lines        8483     8483           
=======================================
  Hits         1333     1333           
  Misses       7050     7050           
  Partials      100      100

Impacted Files	Coverage Δ
daemon/mgr/spec_hook.go	0% <0%> (ø)	⬆️

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[rudyfly]

The title should be: "bugfix: setup hook in advance to avoid panic if no prestart hook setup before"

[allencloud]

I changed the title. What do you think of this pull request?
I wish that you could help to review this, since this is a P0. @rudyfly

[HusterWan]

LGTM

[allencloud]

LGTM