Update git submodules
- Update extensions/AbuseFilter from branch 'REL1_39' to adc48ce69114ff26ecdbdcce7b25e09bcb1744cf
- Merge "build: Update MediaWiki requirement to 1.39.0" into REL1_39
- build: Update MediaWiki requirement to 1.39.0
Change-Id: I2b4bb20eb27bd52f5dd3b48bd84c0af56770d7b3