Fix crash when shooting a bow and having a quiver with bolts

Fixes crash reported there: http://smf.cataclysmdda.com/index.php?topic=7565

Crash happened because the game tried to reload the bow with the ammo in the quiver, which were bolts and can not be used as ammo for a bow. Reloading fails silently and the bow is not loaded (curammo == NULL), which leads to a crash when printing "Shoting x from y" in the targeting window. The changes checks that the items in the quiver have the same ammo type as the weapon, a quiver with bolts is therefor not considered with a bow.

I removed the check `if (u.weapon.ammo_type() == "arrow")`, this is now implicitly done  when checking the ammo in the quiver against the weapon.