enhance: do not refresh commit details if the new selected commit points to the same revision with old one (#1989)

Signed-off-by: leo <longshuang@msn.cn>

src/ViewModels/CommitDetail.cs

@@ -53,6 +53,9 @@ namespace SourceGit.ViewModels
             get => _commit;
             set
             {
+                if (_commit != null && value != null && _commit.SHA.Equals(value.SHA, StringComparison.Ordinal))
+                    return;
+
                 if (SetProperty(ref _commit, value))
                     Refresh();
             }