Update flags.bzl

Author: alexeagle

protoc/flags.bzl

@@ -13,8 +13,7 @@ PROTOC_TOOLCHAIN_FLAGS = {
             default = "external/.*protobuf.*@--PROTOBUF_WAS_NOT_SUPPOSED_TO_BE_BUILT",
             description = "Make sure protobuf is not built from source",
         ),
-        
-        "per_file_copt": struct(
+        struct(
             default = "external/.*grpc.*@--GRPC_WAS_NOT_SUPPOSED_TO_BE_BUILT",
             description = "Make sure grpc is not built from source",
         ),
@@ -24,7 +23,7 @@ PROTOC_TOOLCHAIN_FLAGS = {
             default = "external/.*protobuf.*@--PROTOBUF_WAS_NOT_SUPPOSED_TO_BE_BUILT",
             description = "Make sure protobuf is not built from source",
         ),
-        "host_per_file_copt": struct(
+        struct(
             default = "external/.*grpc.*@--GRPC_WAS_NOT_SUPPOSED_TO_BE_BUILT",
             description = "Make sure grpc is not built from source",
         ),