make null empty for data_warning in committees

Makefile

@@ -107,6 +107,7 @@ do-import-spreadsheets:
 	csvsql --db postgresql:///$(DATABASE_NAME) --insert --no-create --no-inference $(CSV_PATH)/committees.csv
 	echo 'ALTER TABLE "committees" ADD COLUMN id SERIAL PRIMARY KEY;' | psql $(DATABASE_NAME)
 	./bin/remove-whitespace $(DATABASE_NAME) committees Filer_NamL
+	./bin/make-null-empty $(DATABASE_NAME) committees data_warning
 
 	echo 'DROP TABLE IF EXISTS office_elections CASCADE;' | psql $(DATABASE_NAME)
 	./bin/create-table $(DATABASE_NAME) $(CSV_PATH) office_elections