Fix cancellation on interrupt

Cancel the one-shot state when the interruptor is pressed, not when it is
released. Otherwise, when typing fast, other keys pressed while the interruptor
is still releasing, may have the one-shot effect applied too.

For this to work, we need to do the cancellation post-clear, otherwise the
one-shot modifiers are cleared before they register with the interruptor.

Fixes #1, which used to be keyboardio/Akela#121.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

src/Akela/OneShot.cpp

@@ -190,9 +190,6 @@ namespace Akela {
 
     if (key_is_pressed (keyState)) {
       saveAsPrevious (mappedKey);
-    }
-
-    if (key_toggled_off (keyState)) {
       shouldCancel = true;
     }
 
@@ -204,7 +201,7 @@ namespace Akela {
     if (!State)
       return;
 
-    if (!postClear) {
+    if (postClear) {
       if (Timer < TimeOut)
         Timer++;