[MacPorts] #44208: Update gshhg-gmt 2.3.0 to 2.3.1

[MacPorts]

#44208: Update gshhg-gmt 2.3.0 to 2.3.1
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 Reporter:  florian@…             |      Owner:  macports-tickets@…
     Type:  update                |     Status:  new
 Priority:  Normal                |  Milestone:
Component:  ports                 |    Version:
 Keywords:  haspatch, maintainer  |       Port:  gshhg-gmt
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 Please commit the portfile patch. Thanks.

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Ticket URL: <https://trac.macports.org/ticket/44208>
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