Fix LDFLAGS getting overwritten (ext/curl)

Author: dktapps

ext/curl/config.m4

@@ -99,7 +99,7 @@ if test "$PHP_CURL" != "no"; then
 
     save_CFLAGS="$CFLAGS"
     CFLAGS=$CURL_INCL
-    save_LDFLAGS="$CFLAGS"
+    save_LDFLAGS="$LDFLAGS"
     LDFLAGS=$CURL_LIBS
 
     AC_PROG_CPP