FIX build - add OR empty string

Signed-off-by: Damian Krysta <damian@krysta.dev>

ui/src/Live/Multiview.tsx

@@ -156,7 +156,7 @@ const Multiview = (props: MultiviewProps) => {
   const [selected, updateSelected] = useReducer(
     selectedReducer,
     searchParams.has("cams")
-      ? JSON.parse(searchParams.get("cams"))
+      ? JSON.parse(searchParams.get("cams") || "")
       : Array(MAX_CAMERAS).fill(null)
   );