Solver crashes on some recipes when job level is below 7

[KonaeAkira]

This happens because the StepLbSolver assumes that it is always possible to finish a craft given an infinite amount of CP, which is true when durability-restoring actions like Master's Mend are available. Master's Mend is available at level 7, so below that, the solver crashes.

[KonaeAkira]

Low-priority issue as absolutely no one uses Raphael at such a low level.