Update IAccountServiceForApplication.cs (#85)

Stubs:
- GetUserCount (`Write(0);` throw userland error)

Ryujinx.Core/OsHle/Services/Acc/IAccountServiceForApplication.cs

@@ -13,6 +13,7 @@ namespace Ryujinx.Core.OsHle.Services.Acc
         {
             m_Commands = new Dictionary<int, ServiceProcessRequest>()
             {
+                {   0, GetUserCount                        },
                 {   3, ListOpenUsers                       },
                 {   5, GetProfile                          },
                 { 100, InitializeApplicationInfo           },
@@ -20,6 +21,15 @@ namespace Ryujinx.Core.OsHle.Services.Acc
             };
         }
 
+        public long GetUserCount(ServiceCtx Context)
+        {
+            Context.ResponseData.Write(0);
+
+            Logging.Stub(LogClass.ServiceAcc, "Stubbed");
+
+            return 0;
+        }
+
         public long ListOpenUsers(ServiceCtx Context)
         {
             Logging.Stub(LogClass.ServiceAcc, "Stubbed");
@@ -48,4 +58,4 @@ namespace Ryujinx.Core.OsHle.Services.Acc
             return 0;
         }
     }
-}
+}