Win32: restore UPDATE_SOURCES in tags build script.

The parameter has been obsoleted recently, but older
tags may still depend on its availability and the tag script is
supposed to be capable of building older tags as well.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@22319 57a11ea4-9604-0410-9ed3-97b8803252fd

packaging/win32/build_tags_git.sh

@@ -91,6 +91,12 @@ for tag_rev in $tags ; do
   echo -n 'GLOBAL_DIR=c:\\soft\\gnucash-' >> ${w32pkg}/custom.sh
   echo "${tag}" >> ${w32pkg}/custom.sh
 
+  # UPDATE_SOURCES is obsolete, but preserved here to allow the
+  # current script to also build older tags, that may still
+  # use this parameter.
+  # No need to update the sources we just checked out
+  echo "UPDATE_SOURCES=no" >> ${w32pkg}/custom.sh
+
   # BUILD_FROM_TARBALL is special:
   # in install.sh place we check !=yes, in defaults.sh =yes, in dist.sh =no
   # We want it to look like 'no' in install and defaults, but yes in dist