Comment 3 for bug 1646595

This patch eliminates bogus path elements in Hershey Text containing spaces. Previously, when draw_svg_text() was asked to render a space, it generated a path element that contained just a number, which happened to be the character cell width, instead of a proper path starting with an "M" (moveto).

Malformed path elements can crash other extensions, such as cubicsuperpath.py.