Make sure when we have no update and no download url we show the correct message

[zero-24]

Pull Request for Issue raised by @franz-wohlkoenig

Summary of Changes

Make sure when we have no update and no download url we show the correct message

Testing Instructions

Install 3.9.12-dev
switch to the default update server (which does not know anything about 3.9.12 yet)
Joomla claims it found an update but could not found an download URL wich is not true
apply this patch
notice the correct message comes up
switch to the nighlty update server: https://update.joomla.org/core/nightlies/next_patch_list.xml (which knows of the existence of the 3.9.12-dev)
notice the reinstall message comes up

Expected result

Actual result

Documentation Changes Required

none.

[ghost]

I have tested this item ✅ successfully on 3352704

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[viocassel]

I have tested this item ✅ successfully on 3352704

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/26076.}

[alikon]

RTC

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/26076.}

[wilsonge]

Thanks!