[gimp] meson: -Dwindows-installer also works on Linux build machine.

[Jehan <jehanp src gnome org>]

commit a8f020d889f68bf31ee7a836b31fe7eacd41b48d
Author: Jehan <jehan girinstud io>
Date:   Tue May 18 20:21:18 2021 +0200

    meson: -Dwindows-installer also works on Linux build machine.
    
    To this day, the windows-installer option only creates the language
    files for the installer. There is just no reason to forbid building them
    (hence testing the option works) on non-Windows platforms. In autotools,
    it already works fine on all platforms.

 meson.build | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)
---
diff --git a/meson.build b/meson.build
index 94f9b23197..cf1e3e8463 100644
--- a/meson.build
+++ b/meson.build
@@ -1610,13 +1610,9 @@ meson.add_dist_script('meson_dist_script.sh')
 rootInclude = include_directories('.')
 appInclude  = include_directories('app')
 
-if platform_windows
-  subdir('build/windows')
-
-  if get_option('windows-installer')
-    subdir('po-windows-installer')
-    subdir('build/windows/installer')
-  endif
+if get_option('windows-installer')
+  subdir('po-windows-installer')
+  subdir('build/windows/installer')
 endif
 
 # Tools