Changed enchant_weapon to not duplicate applies

This would fix issue #175. Prevent enchant_weapon in spells.c from duplicating applies.

What the code intended was to move all the applies down 2 positions so that the new damroll/hitroll could be added to the top. What it actually did was duplicate them 2 positions down, hence all the duplicate applies.

The change removes the section of duplication, and instead just has the new hitroll and damroll overwrite whatever is in the first two apply slots. This is similar to what damn and bless do, so I feel it is an adequate fix.

A thought would be to have it completely wipe the item of applies, and then add the hit and damroll. I like it just wiping the first two, adds flavor.