Windows: 64-bit fix for build-binary.pl
diff --git a/win32/dist/build-binary.pl b/win32/dist/build-binary.pl
index 0a88b3b..b064cc8 100755
--- a/win32/dist/build-binary.pl
+++ b/win32/dist/build-binary.pl
@@ -40,7 +40,10 @@
 }
 die("makensis.exe not found") if (!(-f $makensis));
 
-my $openssldir = $ENV{TARGET_CPU} eq "x64" ? "C:\\OpenSSL-Win64" : "C:\\OpenSSL-Win32";
+my $target_arch = $ENV{TARGET_CPU} ? $ENV{TARGET_CPU} : $ENV{Platform} ?
+                  $ENV{Platform} : "x86";
+my $openssldir = $target_arch eq "x64" ? "C:\\OpenSSL-Win64" :
+                 "C:\\OpenSSL-Win32";
 my $opensslincdir = $openssldir . "\\include";
 my $openssllibdir = $openssldir . "\\lib\\VC";