logging: Use RedirectStdLog to capture more stdlib logs (#4732)

* logging: Use `RedirectStdLog`

* .gitignore a file pattern that I'm constantly using for testing

.gitignore

@@ -1,6 +1,7 @@
 _gitignore/
 *.log
 Caddyfile
+Caddyfile.*
 !caddyfile/
 
 # artifacts from pprof tooling

logging.go

@@ -661,9 +661,15 @@ func newDefaultProductionLog() (*defaultCustomLog, error) {
 
 	cl.buildCore()
 
+	logger := zap.New(cl.core)
+
+	// capture logs from other libraries which
+	// may not be using zap logging directly
+	_ = zap.RedirectStdLog(logger)
+
 	return &defaultCustomLog{
 		CustomLog: cl,
-		logger:    zap.New(cl.core),
+		logger:    logger,
 	}, nil
 }