Log Message:
gnucash: update to 2.6.21.

The GnuCash development team announces GnuCash 2.6.21, the twenty-second and \ 
final, final maintenance release in the 2.6-stable series.

Between 2.6.19 and 2.6.21, the following bugfixes were accomplished:

    * Bug 795049 - GnuCash 2.6.20-1 (Fedora Linux package) is unable to open \ 
MariaDB database.
    * Bug 795068 - src/optional/python-bindings missing several files.
    * Bug 795078 - missing _inflateValidate symbol has recurred in 2.6.20 on MacOS.

Between 2.6.19 and 2.6.20, the following bugfixes were accomplished:

    * Bug 765846 - Expense Over Time for subaccounts: An error occurred while \ 
running the report: Fix crash if acc-depth too low.
    * Bug 791848 - GC 2.6.x does not handle ISO dates introduced with GC 2.7 \ 
Enable reading ISO-formatted dates, recognize GNC_FEATURE_SQLITE3_ISO_DATES.
    * Bug 792008 - gnucash 2.6.19 fails to build Replace g_assert_true with \ 
g_assert for now
    * Bug 793278 - wrong data in charts with accumulated values (like \ 
"net-linechart", "net-barchart" and "liabilities \ 
barchart")
    * Bug 794030 - relative date functions compute wrong day of month
    * Bug 790526 - Mathematical bug This change will fix \ 
'num-of-weeks-since-1/jan/1970' which formerly used quotient to remove the \ 
fractional part of the division. For negative values of num-of-weeks, the number \ 
is truncated in the wrong direction (i.e. towards 0). This change uses floor \ 
instead to ensure the num-of-weeks found is the nearest integer LESS than the \ 
fractional number.

Some other fixes not associated with reported bugs:

    * Online HBCI actions: Remove outdated non-SEPA menu items.
    * Add XML namespaces for all Account Hierarchy Templates.
    * General cleanup of Account Hierarchy Templates.
    * Fix auto-selection of splits in reconcile. Really use all splits of any \ 
given day. Up to now usually the splits of the given date were not or not all \ 
included, as the time comparison didn't correctly ignore any given time-of-day \ 
of the splits. Instead, all possible time-of-days should be included.
    * Properly detect git in case of linked worktree.
    * Account Hierarchy for India: Set LANGUAGE=hi and LANG=en_IN to access it.
    * Improve Import menu entries Customer & vendors use same menu label as \ 
others, replace template by tooltip, add ellipsis to entry, add comments to \ 
distinguish "Import" as verb and substantive.
    * Provide preference panel to set the Alpha Vantage API key needed for \ 
Finance::Quote.
    * Correct the appstream definition to match the current spec.
    * Fix collectors and min-date handling in reports.