[gimp] build: Windows installer version deduced from configure.ac.

[Jehan <jehanp src gnome org>]

commit f98ccf5b322300c44a0d4e8a84b889c3145c663b
Author: Jehan <jehan girinstud io>
Date:   Mon May 17 16:03:24 2021 +0200

    build: Windows installer version deduced from configure.ac.
    
    I left the version I was using while testing, but this is obviously
    wrong as we would always forget to update it (actually even now it was
    wrong as it was producing an installer versionned 2.99.6 whereas it
    should have been 2.99.7!). Instead let's grep the major/minor/micro from
    the build system.

 build/windows/gitlab-ci/installer-gimp-msys2.sh | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/build/windows/gitlab-ci/installer-gimp-msys2.sh b/build/windows/gitlab-ci/installer-gimp-msys2.sh
index 8ac89e6645..29089b1c42 100644
--- a/build/windows/gitlab-ci/installer-gimp-msys2.sh
+++ b/build/windows/gitlab-ci/installer-gimp-msys2.sh
@@ -28,5 +28,8 @@ wget https://raw.githubusercontent.com/jrsoftware/issrc/main/Files/Languages/Uno
 cd -
 
 # Construct now the installer.
+MAJOR_VERSION=`grep 'm4_define(\[gimp_major_version' configure.ac |sed 
's/m4_define(\[gimp_major_version.*\[\([0-9]*\)\].*/\1/'`
+MINOR_VERSION=`grep 'm4_define(\[gimp_minor_version' configure.ac |sed 
's/m4_define(\[gimp_minor_version.*\[\([0-9]*\)\].*/\1/'`
+MICRO_VERSION=`grep 'm4_define(\[gimp_micro_version' configure.ac |sed 
's/m4_define(\[gimp_micro_version.*\[\([0-9]*\)\].*/\1/'`
 cd build/windows/installer
-./compile.bat 2.99.6 ../../.. gimp-w32 gimp-w64 ../../.. gimp-w32 gimp-w64
+./compile.bat ${MAJOR_VERSION}.${MINOR_VERSION}.${MICRO_VERSION} ../../.. gimp-w32 gimp-w64 ../../.. 
gimp-w32 gimp-w64