fix: Removed CMD from dockerfile as not needed

Dockerfile

@@ -19,4 +19,3 @@ COPY --from=build /etc/passwd /etc/passwd
 
 USER nobody
 ENTRYPOINT ["/cloudflare-ddns-updater"]
-CMD ["cloudflare-ddns-updater"]

internal/config.go

@@ -71,14 +71,13 @@ func (c Config) Validate() error {
 func NewConfig() Config {
 	checkInterval, err := strconv.ParseInt(os.Getenv(envKeyCheckIntervalSeconds), 10, 64)
 	if err != nil {
-		log.Printf("wrong `%s` value. Check interval set default(%ds)", envKeyCheckIntervalSeconds, defaultCheckInterval)
+		log.Printf("wrong or missing `%s` value. Check interval set to default(%ds)", envKeyCheckIntervalSeconds, defaultCheckInterval)
 		checkInterval = defaultCheckInterval
 	}
 
 	return Config{
 		DnsRecordsToCheck:         parseCommaDelimited(os.Getenv(envKeyDnsToCheck)),
 		DNSProviderTag:            getEnvDefault(envKeyDNSProviderTag, "cloudflare"),
-		PublicDNSServer:           getEnvDefault(envKeyPublicDNSServer, "1.1.1.1"),
 		PublicIpResolverTag:       getEnvDefault(envKeyPublicIpResolverTag, "icanhazip"),
 		ApiToken:                  os.Getenv(envKeyCloudflareApiKey),
 		CloudflareZone:            os.Getenv(envKeyCloudflareZone),