THRIFT-4166: fix recent VC2010 build regression and prevent it in the future
Client: cpp

This closes #1237
diff --git a/build/appveyor/MSVC-appveyor-build.bat b/build/appveyor/MSVC-appveyor-build.bat
index ee022cb..054a8b4 100644
--- a/build/appveyor/MSVC-appveyor-build.bat
+++ b/build/appveyor/MSVC-appveyor-build.bat
@@ -35,6 +35,7 @@
     -DZLIB_LIBRARY="%WIN3P%\zlib-inst\lib\zlib%ZLIB_LIB_SUFFIX%.lib" ^
     -DZLIB_ROOT="%WIN3P%\zlib-inst" ^
     -DWITH_PYTHON=%WITH_PYTHON% ^
+    -DWITH_%THREADMODEL%THREADS=ON ^
     -DWITH_SHARED_LIB=OFF ^
     -DWITH_STATIC_LIB=ON                    || EXIT /B
 @ECHO OFF