Bump Google.Protobuf from 3.10.1 to 3.15.0 in /Time.Server#1

dependabot[bot] wants to merge 1 commit intomasterNFive/plugin-time:masterfrom

dependabot/nuget/Time.Server/Google.Protobuf-3.15.0NFive/plugin-time:dependabot/nuget/Time.Server/Google.Protobuf-3.15.0Copy head branch name to clipboard