item speed modifiers stack.

[Erik]

Bug Description:

You can stack movement speed modifiers by putting them in your hand(s) and feet.

Steps to reproduce:

1. Grab any pair of boots that have a movement speed modifier and put them in your hand.
   
2. Run faster.
   
3. Grab another pair of movement speed modifier boots and hold them in your hand.
   
4. Run even faster.
   

Steps to fix:

1. Exclude l_hand and r_hand from the respective proc that counts movement speed modifiers.