Texture width is recalculated larger on subsequent call to updateText() when text has a stroke thickness > 1

In function override Phaser.Text.prototype.updateText(), don't include this.context.lineWidth in width calculation as it's already incorporated by this.style.strokeThickness.
Merge pull request #1261 from spayton/dev

Texture width is recalculated larger on subsequent call to updateText() ...