Remove deprecated switch to disable warning.

contrib/zlib/CMakeLists.txt

@@ -76,15 +76,7 @@ if(MSVC)
     set(CMAKE_DEBUG_POSTFIX "d")
     add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
     add_definitions(-D_CRT_NONSTDC_NO_DEPRECATE)
-    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" ) # clang-cl
-        #SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-deprecated-non-prototype")
-    endif()
-
     include_directories(${CMAKE_CURRENT_SOURCE_DIR})
-else()
-    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" ) # clang-cl
-        #SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-deprecated-non-prototype")
-    endif()
 endif()
 
 if(NOT CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_CURRENT_BINARY_DIR)