Player text objects with invalid texture data use the missing texture rather than falling back to a player texture

If a text object that displays a player’s face is provided with invalid texture data, the missing texture (a section thereof) is displayed, rather than falling back to one of the default player skins like in other cases.

Example commands:

/tellraw @p {"player":{"name":"",texture:"error"}}

/tellraw @p {"player":{"name":"#"}}

Expected results: both of these would display one of the default skins.

Actual results: the bottom one correctly displays Steve, but the top incorrectly displays a magenta square.