[build] gn format

Change-Id: I00baf4fc7981d48f69f070c184820c7dddd30f71
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/protobuf/+/441767
Reviewed-by: Oliver Newman <olivernewman@google.com>
diff --git a/proto_library.gni b/proto_library.gni
index 2224801..1ddf7dd 100644
--- a/proto_library.gni
+++ b/proto_library.gni
@@ -302,7 +302,8 @@
     }
 
     if (defined(invoker.use_protobuf_full)) {
-      args += ["--import-dir=" + rebase_path("//third_party/protobuf/src", root_build_dir)]
+      args += [ "--import-dir=" +
+                rebase_path("//third_party/protobuf/src", root_build_dir) ]
     }
 
     # System protoc is not used so it's necessary to build one.