Fix log filename issue on Windows

internal/app.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	netHttp "net/http"
 	"os"
+	"strings"
 	"time"
 
 	// _ "net/http/pprof" // Register pprof
@@ -30,7 +31,9 @@ func MainApp(configPath string) {
 	utils.EnsureDirExists("data/info")
 	utils.EnsureDirExists("dump") // "zurgtorrent" files
 
-	logPath := fmt.Sprintf("logs/zurg-%s-%s.log", time.Now().Format(time.DateOnly), time.Now().Format(time.TimeOnly))
+	dateStr := time.Now().Format(time.DateOnly)
+	timeStr := strings.ReplaceAll(time.Now().Format(time.TimeOnly), ":", "-")
+	logPath := fmt.Sprintf("logs/zurg-%s-%s.log", dateStr, timeStr)
 	log := logutil.NewLogger(logPath)
 
 	zurglog := log.Named("zurg") // logger for this main function