CreateImageWizard: Show empty available state on failed search

Resolves issue #588. 'No packages found' is now correctly displayed
after a failed search that follows a successful search.

src/Components/CreateImageWizard/formComponents/Packages.js

@@ -114,6 +114,7 @@ const Packages = ({ defaultArch, ...props }) => {
             sortPackages(packagesAvailableFiltered);
             setPackagesAvailableFound(true);
         } else {
+            setPackagesAvailable([]);
             setPackagesAvailableFound(false);
         }
     };