Log Message:
gnucash: update to 2.6.19.

Between 2.6.18 and 2.6.19, the following bugfixes were accomplished:

    Bug 787497 - Disabling OFX, AqBanking or python-bindings support
    cripples the dist build target. (Partial: The requisite files
    for AQB and OFX are provided. There remain ways to break the
    distribution.)
    Bug 789928 - FTBFS with libdbi 0.9.0-5 on Debian
    Failed to create file
    "/usr/share/glib-2.0/schemas/gschemas.compiled.XY789Y".

Some other fixes not associated with reported bugs:

    A better way to handle MySQL's 0000-00-00 invalid date indicator.
    Fix python build and test errors on Mac.
    Add translator hint comments to C and glade files.
    Improve type of bank accounts in SKR03
    Stop testing GObject's handling of invalid parameters