Correct spelling of hpi.pluginChangelogUrl tag

[MarkEWaite]

Spell hpi.pluginChangelogUrl property correctly

Plugin version 1.35 includes the correct entry in the manifest already, even though the hpi property name is incorrect. I don't know why that works, but I confirmed that it already works, even without this change. This change will make the file consistent with the property that is already being written into the manifest.

Plugin-ChangelogUrl: https://github.com/jenkinsci/configuration-as-code-plugin/releases

See JENKINS-45740 for details of the commit that provided this originally.

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[codecov]

Codecov Report

Merging #1248 into master will decrease coverage by 0.02%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #1248      +/-   ##
============================================
- Coverage     78.96%   78.93%   -0.03%     
  Complexity      780      780              
============================================
  Files            65       65              
  Lines          2301     2298       -3     
  Branches        321      318       -3     
============================================
- Hits           1817     1814       -3     
  Misses          383      383              
  Partials        101      101

Impacted Files	Coverage Δ	Complexity Δ
...ava/io/jenkins/plugins/casc/TokenReloadAction.java	95% <0%> (-0.24%)	11% <0%> (ø)
...java/io/jenkins/plugins/casc/BaseConfigurator.java	83.75% <0%> (-0.17%)	69% <0%> (ø)