minor copypasta fix

Author: mcmonkey4eva

src/BuiltinExtensions/ComfyUIBackend/ComfyUISelfStartBackend.cs

@@ -447,7 +447,7 @@ string getVers(string package)
                 await update("numpy", "numpy>=1.25.0");
             }
             string avVers = getVers("av");
-            if (numpyVers is not null && Version.Parse(numpyVers) < Version.Parse("14.2.0"))
+            if (avVers is not null && Version.Parse(avVers) < Version.Parse("14.2.0"))
             {
                 await update("av", "av>=14.2.0");
             }