gui: bump theme version to 4

updates to reboot page (change to listbox)

Change-Id: I02331693ca9a407e0bd30c633f2b799ece7b3636
diff --git a/gui/theme/portrait_mdpi/splash.xml b/gui/theme/portrait_mdpi/splash.xml
index f8c695f..4ce64b3 100644
--- a/gui/theme/portrait_mdpi/splash.xml
+++ b/gui/theme/portrait_mdpi/splash.xml
@@ -5,7 +5,7 @@
 		<author>TeamWin</author>
 		<title>TWRP</title>
 		<description>splash screen</description>
-		<themeversion>3</themeversion>
+		<themeversion>4</themeversion>
 	</details>
 
 	<resources>