Remove test_recognize_digits_mlp from Mac

test=develop

python/paddle/fluid/tests/book/high-level-api/recognize_digits/CMakeLists.txt

@@ -10,6 +10,8 @@ else()
     foreach(src ${TEST_OPS})
         if(${src} STREQUAL "test_recognize_digits_conv")
             message(WARNING "These tests has been disabled in OSX for random fail: \n" ${src})
+        elseif(${src} STREQUAL "test_recognize_digits_mlp")
+            message(WARNING "These tests has been disabled in OSX for random fail: \n" ${src})
         else()
             py_test(${src} SRCS ${src}.py)
         endif()