Add trustServerCertificate=true to the connection URL to not validate the server TLS/SSL certificate or import the certificate to the Foglight TrustStore.
For a Foglight upgrade
server.database.url = "jdbc:sqlserver://;serverName=servername;portNumber=1433;database=Foglight;encrypt=false;integratedSecurity=true;trustServerCertificate=true";
server.database.url = "jdbc:sqlserver://;serverName=servername;portNumber=1433;database=Foglight;encrypt=false;trustServerCertificate=true";
For a new Foglight installation