gui: make tw_show_kb non-persistent

Change-Id: Icb3dd2342cc3bdc349aaf933d306b9f5315d1e98
Signed-off-by: z31s1g <z31s1g@googlemail.com>
diff --git a/gui/theme/watch_mdpi/ui.xml b/gui/theme/watch_mdpi/ui.xml
index 163a82b..bad23c0 100644
--- a/gui/theme/watch_mdpi/ui.xml
+++ b/gui/theme/watch_mdpi/ui.xml
@@ -76,8 +76,7 @@
 	</resources>
 
 	<variables>
-		<variable name="tw_hide_kb" value="0" persist="1"/>
-
+		<variable name="tw_hide_kb" value="0"/>
 		<variable name="screen_width" value="320"/>
 		<variable name="screen_half_width" value="160"/>
 		<variable name="screen_height" value="320"/>