fix create RpcClient with param HttpClient not set BaseAddress

[tqk2811]

Status	Type	⚠️ Core Change	Issue
Ready	Bug	No

Problem

Create IRpcClient with param HttpClient not set HttpClient.BaseAddress cause request failed

Solution

Solnet/src/Solnet.Rpc/Core/Http/JsonRpcClient.cs

Line 55 in 99504b6

_httpClient = httpClient ?? new HttpClient { BaseAddress = NodeAddress };

- _httpClient = httpClient ?? new HttpClient { BaseAddress = NodeAddress };
+ _httpClient = httpClient ?? new HttpClient();
+ _httpClient.BaseAddress = NodeAddress;