Update git submodules
- Update extensions/JsonConfig from branch 'wmf/1.29.0-wmf.12'
- Remove the '+' in 'CC0-1.0+'
It implies future versions of the CC0 license, which doesn't make sense.
Bug: T154075 Change-Id: I2b8edfcc4b02e90da71793aaf0eb9013e661d091 (cherry picked from commit a05c5aab4d4c916fd49bb5d27e41c688d411e1e2)
- Remove the '+' in 'CC0-1.0+'