Allow use of cached renewal for more than 1 day

[barrar]

I use win-acme in a dev environment where websites are built many times per week. Every build runs win-acme to ensure SSL will work regardless of any changes that may have been made (e.g. the website was deleted and recreated or hostname changes). The bindings are reset every build by Octopus, and win-acme conveniently adds the certificate and bindings.

This is the code that is ran:
C:\win-acme.v2.0.7.315\wacs.exe --installation iis --installationsiteid $IISWebsiteID --target iissite --siteid $IISWebsiteID

With the latest build of win-acme, if the certificate has already been generated in the last 24 hours the certificate is reused. I increased this to 20 days and I no longer run into rate limits.

src/main/Services/CertificateService.cs line 170
Before: cache.CacheFile.LastWriteTime > DateTime.Now.AddDays(-1)
After cache.CacheFile.LastWriteTime > DateTime.Now.AddDays(-20)

This could be implemented as a flag or simply increased to at least a week. As seen at https://letsencrypt.org/docs/rate-limits/, the limit for renewals is 5 per week.

[WouterTinus]

Good idea, won't be too difficult to make it a user setting.

[WouterTinus]

This has been released in version 2.0.8