scr_xpscale PR was done incorrectly

[diamante0018]

Very good first issue

scr_xpscale was not unlocked at all by #26 and setting it to anything higher than 4 will close the game

See: #26 (comment)

[diamante0018]

For reference since perhaps someone needs a little helping hand for this great first issue anyone with notepad can do here is how the bug was fixed on iw6

https://git.alterware.dev/alterware/iw6-rawfiles/commit/c615cf179290a8bdcad5c9d088c2c1b254bd6751