fix exp to level values

[hiperesp]

references:

• https://github.com/hiperesp/DragonFable-Private-Server/issues
• https://forums2.battleon.com/f/tm.asp?m=18647631

[hiperesp]

1 - 59: ok
60+: missing correct logic, using 20+ logic.

[hiperesp]

fixed. missing 90+ logic.