Fix SVGLoader strokes not rendering in Firefox

[yomboprime]

In Firefox the strokeWidth style property parsed by SVGLoader is being added the string "px" at the end, which results in NaN values inserted in the stroke geometry.

This fixes #17647

To be corrected when SVG units are implemented in #17630

[Mugen87]

I can confirm strokes are rendered correctly now in FF.

[mrdoob]

Thanks!

[Mugen87]

@yomboprime You've updated only the jsm version but not the js file. Fixed this with c2cf0d9. Otherwise node utils/modularize.js would undo your PR.

[yomboprime]

@yomboprime You've updated only the jsm version but not the js file. Fixed this with c2cf0d9. Otherwise node utils/modularize.js would undo your PR.

Thanks, I forgot the other version.