Debug: fix disable block linking option

Previously it did the opposite of what it was supposed to; when checked, it'd
turn block linking on, and when unchecked, it'd turn it off.

Also update JITIL's block linking disabling in debug mode to match the behavior
of the regular JIT.
Merge pull request #1240 from FioraAeterna/fixdebugblocklink

Debug: fix disable block linking option