Sticky layer not released with sticky key and key with modifier

[xudongzheng]

To reproduce:

1. Press and immediately release &sk LSFT on layer 0 with quick-release enabled for &sk.
2. Press and immediately release &sl 2 to go to layer 2.
3. Press and immediately release &kp RA(N) on layer 2 twice - it appears that keymap does not revert to layer 0 after the first press though it does revert after the second press.

A few observations:

• This issue does not occur if &kp LSFT is used instead of &sk LSFT.
• This issue does not occur if &kp N is used instead of &kp RA(N).
• This issue does not occur if &sk LSFT is held throughout 2 and 3.
• This issue does not occur without quick-release for &sk.

This combination is useful for languages such as Spanish where you can have &kp RA(N) defined for ñ and use it in conjunction with &sk LSFT to get Ñ.