Fix autogen.sh warning about PKG_CONFIG_MIN_VERSION.

Lower-case that word in macros/pkg.m4 to avoid the need to run
autogen.sh twice.


git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@15693 57a11ea4-9604-0410-9ed3-97b8803252fd

macros/pkg.m4

@@ -20,8 +20,8 @@ AC_DEFUN([PKG_CHECK_MODULES], [
      echo "*** to the full path to pkg-config."
      echo "*** Or see http://www.freedesktop.org/software/pkgconfig to get pkg-config."
   else
-     PKG_CONFIG_MIN_VERSION=0.9.0
-     if $PKG_CONFIG --atleast-pkgconfig-version $PKG_CONFIG_MIN_VERSION; then
+     pkg_config_min_version=0.9.0
+     if $PKG_CONFIG --atleast-pkgconfig-version $PKG_config_min_version; then
         AC_MSG_CHECKING(for $2)
 
         if $PKG_CONFIG --silence-errors --exists "$2" ; then
@@ -47,7 +47,7 @@ AC_DEFUN([PKG_CHECK_MODULES], [
         AC_SUBST($1_CFLAGS)
         AC_SUBST($1_LIBS)
      else
-        echo "*** Your version of pkg-config is too old. You need version $PKG_CONFIG_MIN_VERSION or newer."
+        echo "*** Your version of pkg-config is too old. You need version $pkg_config_min_version or newer."
         echo "*** See http://www.freedesktop.org/software/pkgconfig"
      fi
   fi