pin instanceAccountID to in-process emoji

internal/media/processingemoji.go

@@ -37,6 +37,9 @@
 type ProcessingEmoji struct {
 	mu sync.Mutex
 
+	// id of this instance's account -- pinned for convenience here so we only need to fetch it once
+	instanceAccountID string
+
 	/*
 		below fields should be set on newly created media;
 		emoji will be updated incrementally as media goes through processing
@@ -370,6 +373,7 @@ func (m *manager) preProcessEmoji(ctx context.Context, data DataFunc, shortcode
 	}
 
 	processingEmoji := &ProcessingEmoji{
+		instanceAccountID: instanceAccount.ID,
 		emoji:             emoji,
 		data:              data,
 		staticState:       received,