Ill named binary for plantuml

[informatimago (Pascal J. Bourguignon)]

The binary for plantuml is named: /opt/local/bin/plantuml.sh* This is wrong.

Unix scripts should not have any file extension.

• They unnecessarily expose implementation detail (breaking encapsulation).
• They uselessly and incompletely mimic detail from the #! line.
• They capture insufficient detail to be useful at the system level (and aren't used).
• They clash with recommended Unix (and Linux) practice.
• They add noise to the command-level API.
• They are very commonly technically incorrect for the script.
• They give incorrect impressions about the use of the files they adorn.
• They aren't validated even for what little info is present in them.
• They interfere with switching scripting languages.
• They interfere with changing scripting language versions.
• They interfere with changing to presumably-faster compiled forms.
• They encourage naively running scripts with the extension-implied interpreter.
• They infect novice scripters with misinformation about Unix scripting.
• They ironically are only a problem when interpreted by humans.

See more at:

​http://www.talisman.org/~erlkonig/documents/commandname-extensions-considered-harmful

[ryandesign (Ryan Carsten Schmidt)]

In a96bcc17eaa9e3ec232f8b56d3fb8fc33b06ac15/macports-ports (master):

plantuml: Update to 1.2019.4

And don't use .sh suffix on wrapper script.

Closes: #58340