[gtk+] Visual Studio builds: Fix .pc generation

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

commit 9d8b07d1504f1400748860c4bcc41c0866ec53b7
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Fri Dec 30 15:10:12 2016 +0800

    Visual Studio builds: Fix .pc generation
    
    A space was missed...

 build/win32/gtkpc.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/build/win32/gtkpc.py b/build/win32/gtkpc.py
index 919bfa9..96ef6dc 100644
--- a/build/win32/gtkpc.py
+++ b/build/win32/gtkpc.py
@@ -43,7 +43,7 @@ def main(argv):
     gdk_args = gdk_parser.parse_args()
     if getattr(gdk_args, 'vulkan', None) is 1:
         # On Visual Studio, we link to zlib1.lib
-        vulkan_extra_libs = '-lvulkan-1'
+        vulkan_extra_libs = ' -lvulkan-1'
         gdk_backends += ' vulkan'
         cairo_backends += ' cairo'