[glib] config.h.win32.in: Fix previous commit

[Chun-wei Fan <fanchunwei src gnome org>]

commit 9831516835d6c6a16ba64f2ab9bc82a0707d6564
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Fri Sep 15 11:48:58 2017 +0800

    config.h.win32.in: Fix previous commit
    
    We should still let people building via the MSVC projects decide whether
    they use the bundled PCRE sources for building GLib.  Accidentally
    changed it in the previous commit.

 config.h.win32.in |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/config.h.win32.in b/config.h.win32.in
index 99b3457..b607cca 100644
--- a/config.h.win32.in
+++ b/config.h.win32.in
@@ -788,7 +788,8 @@
 #endif
 
 /* using the system-supplied PCRE library */
-#define USE_SYSTEM_PCRE
+/* This is determined in the MSVC projects */
+/* #undef USE_SYSTEM_PCRE */
 
 /* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
    significant byte first (like Motorola and SPARC, unlike Intel). */