fix appveyor mingw64 build
diff --git a/build/appveyor/MING-appveyor-install.bat b/build/appveyor/MING-appveyor-install.bat
index ce8fc7d..1069b05 100644
--- a/build/appveyor/MING-appveyor-install.bat
+++ b/build/appveyor/MING-appveyor-install.bat
@@ -25,13 +25,9 @@
 CALL cl_setenv.bat                         || EXIT /B
 CALL cl_showenv.bat                        || EXIT /B
 
-:: We're going to keep boost at a version cmake understands
-SET BOOSTVER=1.64.0-3
-SET BOOSTPKG=mingw-w64-%MINGWPLAT%-boost-%BOOSTVER%-any.pkg.tar.xz
-SET IGNORE=--ignore mingw-w64-x86_64-boost --ignore mingw-w64-i686-boost
-
 SET PACKAGES=^
   --needed -S bison flex make ^
+  mingw-w64-%MINGWPLAT%-boost ^
   mingw-w64-%MINGWPLAT%-cmake ^
   mingw-w64-%MINGWPLAT%-libevent ^
   mingw-w64-%MINGWPLAT%-openssl ^
@@ -46,10 +42,4 @@
 :: Upgrade things
 %BASH% -lc "pacman --noconfirm -Syu %IGNORE%"                       || EXIT /B
 %BASH% -lc "pacman --noconfirm -Su %IGNORE%"                        || EXIT /B
-%BASH% -lc "pacman --noconfirm %PACKAGES%"                          || EXIT /B
-
-:: Install a slightly older boost (BOOSTVER) as cmake in mingw
-:: does not have built-in dependencies for boost 1.66.0 yet
-:: -- this cuts down on build warning output --
-
-%BASH% -lc "if [[ $(pacman --query | grep '%MINGWPLAT%-boost') ^!= *"%BOOSTVER%"* ]]; then wget http://repo.msys2.org/mingw/%MINGWPLAT%/%BOOSTPKG% && pacman --noconfirm --needed -U %BOOSTPKG% && rm %BOOSTPKG%; fi" || EXIT /B
+%BASH% -lc "pacman --noconfirm %PACKAGES%"                          || EXIT /B
\ No newline at end of file