Ensure CheckUninstallModalHook is called in WPageDialogPeer._show

During code review [1] for JDK-8334509, it was noticed the code at lines 695-707 [2] is not executed if an error occurs.

> It does look odd. Focus would need transferring in both cases I'd expect.

AwtDialog::CheckInstallModalHook() is called right before the page dialog is displayed by using ::PageSetupDlg. So, AwtDialog::CheckUninstallModalHook() needs to be called after it.

[1] https://github.com/openjdk/jdk/pull/19786#discussion_r1645900131
[2] https://github.com/openjdk/jdk/blob/51b0abc87439014c4c5022c0057614f99a741ddd/src/java.desktop/windows/native/libawt/windows/awt_PrintJob.cpp#L695-L707