DownloadURL-list: update issue tracker link in explainer (#1277)

Co-authored-by: Joone Hur <joonehur@microsoft.com>

Author: joone

DownloadURL-list/explainer.md

@@ -4,7 +4,7 @@ Author: [Joone Hur](https://github.com/joone) (Microsoft)
 
 # Participate
 
-- [Issue tracker](https://github.com/MicrosoftEdge/MSEdgeExplainers/labels/DownloadURL)
+- [Issue tracker](https://github.com/MicrosoftEdge/MSEdgeExplainers/labels/DownloadURL-list)
 
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