Multi-Jumping Stops Jumping

**Description**
- Multi-jump sometimes errors out when jumping against the side of a wall.
- Error started after I introduced friction to the physics system.

**Error**
```IndexOutOfRangeException: Index was outside the bounds of the array.```

**Related Code**
```csharp
// Player is always allowed to jump if touching the ground.
// If already in the air, player can only jump if he hasn't met the
// max number of jumps already.
if (this.isGrounded || this.currentNumberJumps < this.maxNumberJumps)
{
Jump(this.jumpPower[currentNumberJumps]);
}
```