build,win: remove unneeded condition from GYP file

The file itself contains include guards, so don't compile it
conditionally.

PR-URL: https://github.com/libuv/libuv/pull/697
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

uv.gyp

@@ -92,6 +92,7 @@
             'src/win/req.c',
             'src/win/req-inl.h',
             'src/win/signal.c',
+            'src/win/snprintf.c',
             'src/win/stream.c',
             'src/win/stream-inl.h',
             'src/win/tcp.c',
@@ -104,13 +105,6 @@
             'src/win/winsock.c',
             'src/win/winsock.h',
           ],
-          'conditions': [
-            ['MSVS_VERSION < "2015"', {
-              'sources': [
-                'src/win/snprintf.c'
-              ]
-            }]
-          ],
           'link_settings': {
             'libraries': [
               '-ladvapi32',