Fix typo

Change-Id: If1f6a1948536f4774756952d2cd4a98cd0a39d2c

Author: wesm

python/CMakeLists.txt

@@ -105,7 +105,7 @@ if ("${COMPILER_FAMILY}" STREQUAL "clang")
   # Cython warnings in clang
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-parentheses-equality")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-constant-logical-operand")
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-missing_declarations")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-missing-declarations")
 
   # We have public Cython APIs which return C++ types, which are in an extern
   # "C" blog (no symbol mangling) and clang doesn't like this