Fix formatting

Author: jcansdale

src/GitHub.InlineReviews/ViewModels/InlineCommentPeekViewModel.cs

@@ -197,7 +197,7 @@ async Task UpdateThread()
             AvailableForComment =
                 file.Diff.Any(chunk => chunk.Lines
                     .Any(line => leftBuffer ?
-                        line.OldLineNumber -1 == lineNumber :
+                        line.OldLineNumber - 1 == lineNumber :
                         line.NewLineNumber - 1 == lineNumber));
 
             var thread = file.InlineCommentThreads?.FirstOrDefault(x =>