Build: Silence CMake warnings about boost version being too new

dep/boost/CMakeLists.txt

@@ -9,7 +9,6 @@
 # implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 
 if(WIN32)
-  set(BOOST_DEBUG ON)
   if(DEFINED ENV{BOOST_ROOT})
     set(BOOST_ROOT $ENV{BOOST_ROOT})
   endif()
@@ -19,6 +18,8 @@ if(WIN32)
   set(Boost_USE_STATIC_RUNTIME     OFF)
 endif()
 
+set(Boost_NO_WARN_NEW_VERSIONS ON)
+
 include (CheckCXXSourceCompiles)
 
 if (WIN32)