Update CMakeLists.txt

Author: egorpugin

CMakeLists.txt

@@ -88,6 +88,9 @@ if (WIN32)
         add_definitions(-D_CRT_SECURE_NO_WARNINGS)
 
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP")
+        if (APPVEYOR)
+            set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W0")
+        endif()
     endif()
 
     set(LIB_Ws2_32 Ws2_32)