Fix crash while editing tools under 64 bits arch.
Fix crash while editing tools under 64 bits arch.

This commit fixes count computation on tools strings array (ie. tool_types).


asmuelle/heekscnc,satovey/heekscnc,asmuelle/heekscnc,jihyun-kim/heekscnc,jihyun-kim/heekscnc,satovey/heekscnc,satovey/heekscnc,jihyun-kim/heekscnc,satovey/heekscnc,asmuelle/heekscnc,asmuelle/heekscnc,jihyun-kim/heekscnc