Refactor fetchMonitorCertificate to throw an error if invald cert

Server/controllers/controllerUtils.js

@@ -17,6 +17,10 @@ const fetchMonitorCertificate = async (sslChecker, monitor) => {
 		const monitorUrl = new URL(monitor.url);
 		const hostname = monitorUrl.hostname;
 		const cert = await sslChecker(hostname);
+		// Throw an error if no cert or if cert.validTo is not present
+		if (cert?.validTo === null || cert?.validTo === undefined) {
+			throw new Error("Certificate not found");
+		}
 		return cert;
 	} catch (error) {
 		throw error;