[gimp] build: improve gimp:build / windows-installer-langs unit test.

[Jehan <jehanp src gnome org>]

commit 9cd9c342516d6b81190a9150b8f7a2554fc7b5ed
Author: Jehan <jehan girinstud io>
Date:   Fri Oct 1 21:17:24 2021 +0200

    build: improve gimp:build / windows-installer-langs unit test.
    
    Also sort the po files to make sure all lists are ordered the same way.

 build/windows/installer/lang/test-installer-langs.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/build/windows/installer/lang/test-installer-langs.sh 
b/build/windows/installer/lang/test-installer-langs.sh
index 35815befd2..01c4ca0549 100755
--- a/build/windows/installer/lang/test-installer-langs.sh
+++ b/build/windows/installer/lang/test-installer-langs.sh
@@ -9,7 +9,8 @@ INSTALLER_LANGS=`grep -rI '^Name:.*MessagesFile' ${GIMP_TESTING_ABS_TOP_SRCDIR}/
 # 'en' doesn't have a gettext file because it is the default.
 INSTALLER_LANGS=`echo "$INSTALLER_LANGS" | tr '\n\r' ' ' | sed 's/\<en\> //'`
 
-PO_LANGS=`ls ${GIMP_TESTING_ABS_TOP_SRCDIR}/po-windows-installer/*.po |sed 
's%.*/po-windows-installer/\([a-zA-Z_]*\).po%\1%'`
+PO_LANGS=`ls ${GIMP_TESTING_ABS_TOP_SRCDIR}/po-windows-installer/*.po | \
+          sed 's%.*/po-windows-installer/\([a-zA-Z_]*\).po%\1%' | sort`
 PO_LANGS=`echo "$PO_LANGS" | tr '\n\r' ' '`
 
 if [ "$PO_LANGS" != "$INSTALLER_LANGS" ]; then