fix(module:date-picker): fix not use onOk the next time show error

[nuonuoge]

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What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
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What is the current behavior?

Issue Number: N/A

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Other information

[codecov]

Codecov Report

Merging #258 into master will decrease coverage by 0.01%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master     #258      +/-   ##
==========================================
- Coverage   86.79%   86.78%   -0.02%     
==========================================
  Files         229      229              
  Lines        7352     7353       +1     
  Branches     1038     1038              
==========================================
  Hits         6381     6381              
- Misses        566      567       +1     
  Partials      405      405

Impacted Files	Coverage Δ
components/date-picker/date-picker.directive.ts	92.3% <0%> (-1.2%)	⬇️

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[nuonuoge]

在不使用ondismiss和onok时，只使用ngmodel双向绑定时，选中某一时间后，再次打开返显不正确