Hotfix Hive 1.17.1

What's Changed

Hot fix, Hive didn't work when "Wohnen" (residential building) and "Bestand" (existing building) was selected in the building input form, because "NaN" for heat recovery wasn't dealt with properly in the core.

• 617 heating demand bestand by @christophwaibel in #803

Full Changelog: v1.17...v1.17.1