Remove spurious "cscript "

Do not add cscript in main.c, instead rely on cscript.exe being added in script.c:

script.c
Line 569 in 17b9375f

	if (asprintf(&cmd, "cscript.exe \"%s\"", vpninfo->vpnc_script) == -1)

This spurious cscript had been forgotten in f3b06b62, back in 2014.