Don't lose optimization flags passed in CFLAGS.

Change r17720 has a typo that causes it to lose all -Ox flags passed in
CFLAGS when it was actually trying to preserve them.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@22236 57a11ea4-9604-0410-9ed3-97b8803252fd

configure.ac

@@ -48,7 +48,7 @@ USER_OPTIMIZATION=""
 for flag in $CFLAGS; do
   tmp_flag=`echo $flag | sed -e 's,-O.,,'`
   if test -z "$tmp_flag"; then
-    USER_OPTIMIZATION="$USER_OPTIMIZATION ${tmp_flag}"
+    USER_OPTIMIZATION="$USER_OPTIMIZATION ${flag}"
   fi
 done