[MacPorts] #53937: upgrade claws-mail to 3.15.0

[MacPorts]

#53937: upgrade claws-mail to 3.15.0
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 Reporter:  pmetzger             |      Owner:
     Type:  update               |     Status:  new
 Priority:  Normal               |  Milestone:
Component:  ports                |    Version:
 Keywords:  haspatch maintainer  |       Port:  claws-mail
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 Enclosed find a portfile diff to upgrade claws-mail to 3.15.0 — I'm the
 maintainer

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Ticket URL: <https://trac.macports.org/ticket/53937>
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