hovertext color bug fix

eliminated the zero-vector returns, no reason for it since g_iTextPrim is defined =LINK_THIS (1) until state default, when it gets replaced with FloatText prim num, if it exists. Eitehr way, it is always going to have a valid prim link number.
Merge pull request #21 from JoyStipe/hovertext_color_fix

hovertext color bug fix