fix #2567 - migrate tenant connection string details from database to appsettings.json

Oqtane.Client/Services/SystemService.cs

@@ -3,6 +3,7 @@ using System.Threading.Tasks;
 using System.Collections.Generic;
 using Oqtane.Documentation;
 using Oqtane.Shared;
+using System.Net;
 
 namespace Oqtane.Services
 {
@@ -32,9 +33,5 @@ namespace Oqtane.Services
         {
             await PostJsonAsync(Apiurl, settings);
         }
-        public async Task UpdateSystemInfoAsync(string settingKey, object settingValue)
-        {
-            await PutJsonAsync($"{Apiurl}/{settingKey}/{settingValue}", "");
-        }
     }
 }