[gtkmm/use-dllexport-3-24-meson: 3/16] NMake Makefiles: Fix previous commit on /utf-8

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

commit 15a1abe7f117dcacfde4863988d97ba456fdc627
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed May 13 11:18:13 2020 +0800

    NMake Makefiles: Fix previous commit on /utf-8
    
    The previous commit only meant "Visual Studio 2017 or later", where it should
    have been "Visual Studio 2015 or later".  Doh :|

 MSVC_NMake/config-msvc.mak | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/MSVC_NMake/config-msvc.mak b/MSVC_NMake/config-msvc.mak
index 444a729e..ec8a3493 100644
--- a/MSVC_NMake/config-msvc.mak
+++ b/MSVC_NMake/config-msvc.mak
@@ -128,7 +128,7 @@ GDKMM_BASE_CFLAGS =         \
        /wd4530 /wd4251 /wd4275 \
        /FImsvc_recommended_pragmas.h
 
-!if $(PDBVER) > 14
+!if $(PDBVER) >= 14
 GDKMM_BASE_CFLAGS =            \
        $(GDKMM_BASE_CFLAGS)    \
        /utf-8 /wd4828  \