refactor: replace deprecated grpc.Dial with grpc.NewClient in code and docs

examples/grpcentity/server.go

@@ -33,13 +33,13 @@ func random(min, max int, src rand.Source) int {
 // 	return min + int(v.Uint64())
 // }
 
-func getString(len int64) string {
+func getString(len int64, src rand.Source) string {
 	temp := ""
 	startChar := "!"
 	var i int64 = 1
 	for {
 		// For getting valid ASCII characters
-		myRand := random(0, 94, rand.NewSource(time.Now().UnixNano()))
+		myRand := random(0, 94, src)
 		newChar := string(startChar[0] + byte(myRand))
 		temp = temp + newChar
 		if i == len {
@@ -75,8 +75,8 @@ func (IoTServer) UpdateSensingData(ctx context.Context, r *protoapi.SensingData)
 }
 
 func (IoTServer) GetRandomPass(ctx context.Context, r *protoapi.RequestPass) (*protoapi.RandomPass, error) {
-	rand.Seed(r.GetSeed())
-	temp := getString(r.GetLength())
+	src := rand.NewSource(r.GetSeed())
+	temp := getString(r.GetLength(), src)
 
 	response := &protoapi.RandomPass{
 		Password: temp,