cmake: Fix DEPENDS of add_custom_command in protobuf_generate

cmake/protobuf-config.cmake.in

@@ -104,7 +104,7 @@ function(protobuf_generate)
       OUTPUT ${_generated_srcs}
       COMMAND  protobuf::protoc
       ARGS --${protobuf_generate_LANGUAGE}_out ${_dll_export_decl}${protobuf_generate_PROTOC_OUT_DIR} ${_protobuf_include_path} ${_abs_file}
-      DEPENDS ${ABS_FIL} protobuf::protoc
+      DEPENDS ${_abs_file} protobuf::protoc
       COMMENT "Running ${protobuf_generate_LANGUAGE} protocol buffer compiler on ${_proto}"
       VERBATIM )
   endforeach()