[pango-display-list] Don't premultiply the colour twice
[pango-display-list] Don't premultiply the colour twice

When rendering a glyph run from a texture we were premultiplying the
colour once in display_list_render() and then again in
display_list_render_texture(). This was causing the color to come out
wrong. This fixes bug #1775.

Thanks to Pierre-Luc Beaudoin for reporting.

Backport from master:

  6a9130f10fe5ed3c78b541cf0d021857efb57cb4

tardyp/clutter,tardyp/clutter,tardyp/clutter