[Rd] "trace" argument in legend() (PR#2578)

[jerome at hivnet.ubc.ca]

Another easy fix for legend() with trace=TRUE would be to
replace "...)" by ", ...)" in this code:
[...]
        if (trace)
            catn("  rect2(", left, ",", top, ", w=", w, ", h=",
                h, "...)", sep = "")
[...]

Cheers,
Jerome