postgis commandline tool has a .exe extension under windows, it should be .pl

[robe]

When I make install, I see postgis.exe

But it's not an executable. So if I try to run in windows, it complains it's a 16-bit app and incompatible with my 64-bit operating system.

Can we just call it postgis.pl so it's clear it's a perl script.

[Sandro Santilli <strk@…>]

In 1f14839/git:

Do not add the .exe suffix on postgis script, for windows

Closes #5321