jansson: Update to version 2.14

jansson: Update to version 2.14

- Update from 2.12 to 2.14
- Update rootfile
- Changelog
   Version 2.14 Released 2021-09-09
    * New Features:
      - Add `json_object_getn`, `json_object_setn`, `json_object_deln`, and the
        corresponding `nocheck` functions. (#520, by Maxim Zhukov)
    * Fixes:
      - Handle `sprintf` corner cases (#537, by Tobias Stoeckmann)
    * Build:
      - Symbol versioning for all exported symbols (#540, by Simon McVittie)
      - Fix compiler warnings (#555, by Kelvin Lee)
    * Documentation:
      - Small fixes (#544, #546, by @i-ky)
      - Sphinx 3 compatibility (#543, by Pierce Lopez)
   Version 2.13.1 Released 2020-05-07
    * Build:
      - Include `jansson_version_str()` and `jansson_version_cmp()` in
        shared library. (#534)
      - Include ``scripts/`` in tarball. (#535)
   Version 2.13 Released 2020-05-05
    * New Features:
      - Add `jansson_version_str()` and `jansson_version_cmp()` for runtime
        version checking (#465).
      - Add `json_object_update_new()`, `json_object_update_existing_new()`
        and `json_object_update_missing_new()` functions (#499).
      - Add `json_object_update_recursive()` (#505).
    * Build:
      - Add ``-Wno-format-truncation`` to suppress format truncation warnings (#489).
    * Bug fixes:
      - Remove ``strtod`` macro definition for MinGW (#498).
      - Add infinite loop check in `json_deep_copy()` (#490).
      - Add ``pipe`` macro definition for MinGW (#500).
      - Enhance ``JANSSON_ATTRS`` macro to support earlier C standard(C89) (#501).
      - Update version detection for sphinx-build (#502).
    * Documentation:
      - Fix typos (#483, #494).
      - Document that call the custom free function to free the return value
        of `json_dumps()` if you have a custom malloc/free (#490).
      - Add vcpkg installation instructions (#496).
      - Document that non-blocking file descriptor is not supported on
        `json_loadfd()` (#503).

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Reviewed-by: Michael Tremer <michael.tremer@ipfire.org>