message: Use better overload for single-character find()
diff: @@ -802,7 +802,7 @@ TEST(RuleBundleTest, ParseRuleBundleIgnoreExtraComma) {
  std::string error;
  bool success = bundle.ParseConfiguration(text, '\n', &error);
  ASSERT_TRUE(success) << error;
  - ASSERT_NE(error.find(","), std::string::npos) << error; // warning report
  + ASSERT_NE(error.find(','), std::string::npos) << error; // warning report
  ASSERT_THAT(bundle.rules, SizeIs(3));
  EXPECT_TRUE(bundle.rules["test-rule-1"].enabled);
  EXPECT_FALSE(bundle.rules["test-rule-2"].enabled);
  