Fix TypeError for missing `element.properties`
Fix TypeError for missing `element.properties`

>> TypeError: Cannot read property 'length' of null
>>     at resources/jsdoc Export JSON/template/publish.js:96:118

Seems to be my fault.

MasahiroWard/MVPgamedev,MasahiroWard/MVPgamedev,photonstorm/phaser-ce,photonstorm/phaser-ce,MasahiroWard/MVPgamedev,natlot/phaser-ce,photonstorm/phaser-ce,photonstorm/phaser-ce,yupaul/phaser-ce,natlot/phaser-ce,MasahiroWard/MVPgamedev,yupaul/phaser-ce,natlot/phaser-ce,yupaul/phaser-ce,natlot/phaser-ce,yupaul/phaser-ce