Removed alpha channel colour settings for non antialized case, to be able to compile wxWidgets driver with wxWidgets 2.6
Removed alpha channel colour settings for non antialized case, to be able to compile wxWidgets driver with wxWidgets 2.6

svn path=/trunk/; revision=8207

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot