fix splash loading with wx3.0

Previously only gray square was shown. Apparently to show splash screen several calls of wx.Yield() are necessary.
Unfortunately splash.IsShowOnScreen() returns always 1 regardless of whether splash is on the screen or not.
this fix is a dirty hack. It just process all events after splash is created during 0.3 seconds.

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<?xml version='1.0' encoding='utf-8'?>

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<BeremizRoot URI_location="LOCAL://">

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  <TargetType/>

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</BeremizRoot>