[Snyk] Security upgrade alpine from latest to 3.15#2

snyk-bot wants to merge 1 commit intomasterwardialer/lightning-network:masterfrom

snyk-fix-4f5aa8f65e2b9d751063d545062ef9c6wardialer/lightning-network:snyk-fix-4f5aa8f65e2b9d751063d545062ef9c6Copy head branch name to clipboard