--gracetime isn't passed along to slop properly

[ben0x539]

As gcc pointed out:

main.cpp:140:53: warning: format ‘%i’ expects argument of type ‘int’, but argument 7 has type ‘char*’ [-Wformat]

This has the effect of passing the pointer's numeric value to slop, resulting in an invocation like slop -b 5 -p 0 -t 2 -g 32358608 -c 0.5,0.5,0.5,1 --min=0 --max=0

I tried to address this in #5 but that approach introduces other issues, so I'm not sure what the preferred fix would be.

[naelstrof]

Haha thanks I didn't notice, my gcc's warnings must be suppressed somehow. It's fixed with f1c7a89.