This is a regression from PR #4615. The underscore for the last 2 chars in "NUMERO D’IMMATRICULATION" is too bold.

URL: http://www.ameli.fr/fileadmin/user_upload/formulaires/S3706.pdf
1.1.215: https://i.imgur.com/up8Y33j.png
0.8.990: https://i.imgur.com/UioZcLB.png

fc1e2483b433134a538cce0acd0ccc76e335cf5f is the first bad commit
commit fc1e2483b433134a538cce0acd0ccc76e335cf5f
Author: Jonas Jenwald
Date:   Fri Apr 11 20:19:39 2014 +0200

```
Enforce minimum line widths
```

const current = this.current;
      const font = current.font;
      const fontSize = current.fontSize;
      const fontDirection = current.fontDirection;
      const spacingDir = font.vertical ? 1 : -1;
      const charSpacing = current.charSpacing;
      const wordSpacing = current.wordSpacing;
      const textHScale = current.textHScale * fontDirection;
      const fontMatrix = current.fontMatrix || FONT_IDENTITY_MATRIX;
      const glyphsLength = glyphs.length;
      const isTextInvisible =
        current.textRenderingMode === TextRenderingMode.INVISIBLE;
      let i, glyph, width, spacingLength;
      if (isTextInvisible || fontSize === 0) {
        return;
      }
      this._cachedGetSinglePixelWidth = null;
      ctx.save();
      ctx.transform.apply(ctx, current.textMatrix);
      ctx.translate(current.x, current.y);
      ctx.scale(textHScale, fontDirection);
      for (i = 0; i < glyphsLength; ++i) {
        glyph = glyphs[i];
        if (isNum(glyph)) {
          spacingLength = (spacingDir * glyph * fontSize) / 1000;
          this.ctx.translate(spacingLength, 0);
          current.x += spacingLength * textHScale;
          continue;
        }
        const spacing = (glyph.isSpace ? wordSpacing : 0) + charSpacing;