Remove workaround for UpdateSearchHost crash

Now that OnStartSearch is updating IGitHubPaneViewModel on the UI
thread, calling SearchAsync with a duplicate query no longer crashes.
We no longer need to trim whitespace and compare.

Author: jcansdale

src/GitHub.VisualStudio/UI/GitHubPane.cs

@@ -177,13 +177,8 @@ void UpdateSearchHost(bool enabled, string query)
             {
                 SearchHost.IsEnabled = enabled;
 
-                var searchString = SearchHost.SearchQuery?.SearchString;
-                if (searchString?.Trim() != query?.Trim())
+                if (SearchHost.SearchQuery?.SearchString != query)
                 {
-                    // SearchAsync will crash the process if we send it a duplicate string.
-                    // There is a SearchTrimsWhitespace setting that makes searched with leading or trailing
-                    // white-space appear as duplicates. We compare the query with trimmed white-space to avoid this.
-                    // https://github.com/github/VisualStudio/issues/1948
                     SearchHost.SearchAsync(query != null ? new SearchQuery(query) : null);
                 }
             }