bugfix: recover from error on new command

Second issue introduced in commit a2451aa26. It's worth checking error
recovery in the simpler test, even though it's technically caught in the
next one. A little redundancy seems good here.

Manual_tests.md

@@ -40,6 +40,12 @@ record those here.
     on.draw = function(
     ```
   Hit F4. Driver shows an error under the definition.
+  Fix the definition:
+    ```
+    on.draw = function()
+    end
+    ```
+  Hit F4. The error disappears.
 
 * clone this repo to a new client app, clear its save dir, run it, run the
   driver, add a definition containing invalid Lua:

live.lua

@@ -94,6 +94,7 @@ function live.update(dt)
     local buf = live.receive_from_driver()
     if buf then
       live.run(buf)
+      Mode = 'run'
       if on.code_change then on.code_change() end
     end
     Live.previous_read = Current_time