Merge topic 'FindProtobuf-depend-protoc'

e380d7c5 FindProtobuf: Make outputs depend on protoc executable

Modules/FindProtobuf.cmake

@@ -183,7 +183,7 @@ function(PROTOBUF_GENERATE_CPP SRCS HDRS)
              "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.pb.h"
       COMMAND  ${PROTOBUF_PROTOC_EXECUTABLE}
       ARGS --cpp_out  ${CMAKE_CURRENT_BINARY_DIR} ${_protobuf_include_path} ${ABS_FIL}
-      DEPENDS ${ABS_FIL}
+      DEPENDS ${ABS_FIL} ${PROTOBUF_PROTOC_EXECUTABLE}
       COMMENT "Running C++ protocol buffer compiler on ${FIL}"
       VERBATIM )
   endforeach()