Proposed fix for issue 5697: Asus Transformer - Blank message bodies

A fix like detailed on IRC.

I only tested this against an ASUS TF300T (4.2.1), ASUS ME302C (4.2.2), Samsung Galaxy S2 (4.1.2) and an Samsung Galaxy Beam (2.3.6).

Details:
loadDataWithBaseURL("http://", content, "text/html", "utf-8", null);
Works everywhere except on ASUS devices.

loadData(content, "text/html", "utf-8");
Does work on ASUS devices but doesn't render utf8 correctly, but breaks message bodies on older ( <? 4.1.2) androids.

loadData(content, "text/html; charset=UTF-8", "utf-8");
Does work AND renders utf8 correctly on ASUS tablets and other (>? 4.1.2) devices, but also breaks message bodies on older androids.