Fix "no session found" from screen

Thanks to Martin Šlapák for reporting this.

Change-Id: Ia557f3ad61c8c75ecc04c4361a4bc8fa501099a1
diff --git a/board/czechlight/common/overlay/root/doit.sh b/board/czechlight/common/overlay/root/doit.sh
index a99405d..203a5a3 100755
--- a/board/czechlight/common/overlay/root/doit.sh
+++ b/board/czechlight/common/overlay/root/doit.sh
@@ -11,6 +11,7 @@
 done
 
 screen -d -m -S s1
+sleep 1
 screen -S s1 -X screen 1 sysrepod -d -l3
 sleep 1
 screen -S s1 -X screen 2 sysrepo-plugind -d -l3