[MacPorts] #53747: lmdb : update to 0.9.19

[MacPorts]

#53747: lmdb : update to 0.9.19
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  Reporter:  RJVB    |      Owner:
      Type:  update  |     Status:  new
  Priority:  Normal  |  Milestone:
 Component:  ports   |    Version:
Resolution:          |   Keywords:  haspatch
      Port:  lmdb    |
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Comment (by RJVB):

 It's not needed in any strict sens of the term. I even have the impression
 that quite a few Portfiles that do check for other OS types (I noticed
 FreeBSD the other day) don't mention this in the platforms statement.

 I wouldn't mind adding the info, but it can give the impression that it's
 non trivial to use the port on another OS or even that there's official
 support. Neither of those impressions would be true. In addition, there
 are lots of ports that work "as is" on Linux. IOW, I never know what
 purpose the `platforms` statement really serves.

 FWIW we wouldn't be having this discussion if my proposition to support an
 else clause for the platform syntax had been implemented already ;)

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Ticket URL: <https://trac.macports.org/ticket/53747#comment:2>
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