Fail to Boot if P2P Not Enabled for OCR

OCR and OCR2 both require P2P.V2 to be enabled with valid listen addresses. In the case that one
or both are enabled, return an error if P2P is not enabled.

core/services/chainlink/application.go

@@ -387,7 +387,7 @@ func NewApplication(opts ApplicationOpts) (Application, error) {
 		peerWrapper = ocrcommon.NewSingletonPeerWrapper(keyStore, cfg.P2P(), cfg.OCR(), cfg.Database(), db, globalLogger)
 		srvcs = append(srvcs, peerWrapper)
 	} else {
-		globalLogger.Debug("P2P stack disabled")
+		return nil, fmt.Errorf("P2P stack required for OCR or OCR2")
 	}
 
 	if cfg.OCR().Enabled() {