gnucash maint: Revert to using numerical indexes for the x-axis on bar charts

[Geert Janssens]

Updated	 via  https://github.com/Gnucash/gnucash/commit/3b21aacb (commit)
	from  https://github.com/Gnucash/gnucash/commit/92fed5b8 (commit)



commit 3b21aacbc8476484f00a4558add9c198b0bdd306
Author: Geert Janssens <janssens-geert at telenet.be>
Date:   Tue Oct 21 17:13:14 2014 +0200

    Revert to using numerical indexes for the x-axis on bar charts
    
    There is a bug in jqplot to prevents stacked charts from
    rendering properly when using strings for x-axis categories:
    https://bitbucket.org/cleonello/jqplot/issue/587/charts-disappear-by-enabling-stackseries



Summary of changes:
 src/report/report-system/html-barchart.scm | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)