Remove owner icon spec from metadata folder icon

[timja]

see jenkinsci/cloudbees-folder-plugin#451, jenkinsci/cloudbees-folder-plugin#450 and jenkinsci/jenkins#10049

This was introduced in massive PR: #58
No idea if its actually used / still needed, will try to investigate.

Testing done

Tests in this plugin are passing
Tested in Bom PCT are passing jenkinsci/bom#4104

I'll try run this with a breakpoint on in a few setups and see if I can hit it

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[timja]

Used in Organisation folders...

[jglick]

Not sure in detail what this code is for, but from the description, it might be used only to set an icon for an org folder. Which is very cosmetic and something we could get rid of if it has some ill effect on performance. Compare jenkinsci/github-branch-source-plugin#700 (comment).

[timja]

Not sure in detail what this code is for, but from the description, it might be used only to set an icon for an org folder. Which is very cosmetic and something we could get rid of if it has some ill effect on performance. Compare jenkinsci/github-branch-source-plugin#700 (comment).

Possibly, doesn't effect performance though just impacting the command palette, I've done a workaround in the folders plugin, not the cleanest but everything works: jenkinsci/cloudbees-folder-plugin#452