Plug-in view context menu shouldn't show "Import As > Source Project" when no source is available

[mickaelistria]

Assuming I have a TP with only the binary bundles in (no source), I go to "Plug-ins" view and right-click on one bundle. I see "Import As > Source Project" suggested.
However, clicking it wouldn't import a source project but would create a project wrapping some jar.
In case the .source bundle is not available, "Import As > Source Project" shouldn't be shown.