More Android trickery (#7059)

* Modernize jit syntax

It's built-in, no need for a require anymore.

* Flag Android should_restrict_JIT again

It's mildly helpful at putting off the inevitable.
(very, very, very, very mildly).

* Bump android-luajit-launcher

https://github.com/koreader/android-luajit-launcher/pull/281

frontend/ui/rendertext.lua

@@ -15,7 +15,7 @@ local bor = bit.bor
 local lshift = bit.lshift
 
 if Device.should_restrict_JIT then
-    require("jit").off(true, true)
+    jit.off(true, true)
 end
 
 --[[