Work around missing InetPtonW

...in certain Windows build environments (whatever it is exactly that causes
some Windows builds to fail with "error C3861: 'InetPtonW': identifier not
found" while others succeed).  Unclear what the original reason was for setting
_WIN32_WINNT here, but removing it hopefully does not break anything.

Change-Id: I83222ad010d428cf2b9c447760ea47381552d04a
diff --git a/sal/Library_sal.mk b/sal/Library_sal.mk
index 12b66dd7..fbf84d7 100644
--- a/sal/Library_sal.mk
+++ b/sal/Library_sal.mk
@@ -213,10 +213,6 @@ else # $(OS) == WNT
))
# .ENDIF

$(eval $(call gb_Library_add_defs,sal,\
	-D_WIN32_WINNT=0x0502 \
))

$(eval $(call gb_Library_add_exception_objects,sal,\
	sal/osl/w32/file \
	sal/osl/w32/file_dirvol \