bug#19179: 25.0.50; Build failure with wrong version in nt/emacs.rc

[Chris Zheng]

With MSYS2/Mingw-w64 combination, compiling the master (HEAD 88871ef)
fails with:
windres -I . -O coff -o emacs.res emacs.rc
C:\msys64\mingw64\bin\windres.exe: emacs.rc:14: syntax error
Makefile:230: recipe for target 'emacs.res' failed
make[2]: *** [emacs.res] Error 1
make[2]: Leaving directory '/home/Kel/repo/emacs/nt'

It seems that `emacs.rc' goes wrong, since the line 14 looks like:
 FILEVERSION ,0,0
but it is expected to be:
 FILEVERSION 25,0,50,0

I think the problem comes from line 1917 in configure.ac, where
`$version' is null.  Although I know little about the configure, I
suspect changing `$version' to `$PACKAGE_VERSION' is OK.  That is, the
below patch.  Am I wrong?  I'm eager to know the solution.  Thank you.

___
        Modified   configure.ac
diff --git a/configure.ac b/configure.ac
index 6b6b1c7..0d12f85 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1914,7 +1914,7 @@ if test "${HAVE_W32}" = "yes"; then
     *) EMACS_MANIFEST="emacs-x86.manifest" ;;
   esac
   dnl Construct something of the form "24,4,0,0" with 4 components.
-  comma_version=`echo "$version.0.0" | sed -e 's/\./,/g' -e 
's/^\([[^,]]*,[[^,]]*,[[^,]]*,[[^,]]*\).*/\1/'`
+  comma_version=`echo "$PACKAGE_VERSION.0.0" | sed -e 's/\./,/g' -e 
's/^\([[^,]]*,[[^,]]*,[[^,]]*,[[^,]]*\).*/\1/'`
 
   comma_space_version=`echo "$comma_version" | sed 's/,/, /g'`
   AC_SUBST(comma_version)