Update tools/cooja submodule

Commits:
979bf199 Merge pull request contiki-ng#111 from pjonsson/update-mspsim
5004dcdf Update mspsim submodule
5789c4ea Merge pull request contiki-ng#90 from pjonsson/stop-boxing
4996eb44 Merge pull request contiki-ng#103 from pjonsson/update-mspsim
ba66e502 Merge pull request contiki-ng#110 from pjonsson/fix-box-deprecation-warnings
177e3a1b Merge pull request contiki-ng#108 from pjonsson/mspsim-ignore-untracked
3479b27a Fix boxing deprecation warnings
3417074d Merge pull request contiki-ng#109 from pjonsson/check-java
f9c4ad8e build.xml: fail on Java < 11
8c393d7b Remove some explicit boxing
b47c4116 Merge pull request contiki-ng#106 from pjonsson/more-unused
4e7d64ef mspsim: ignore untracked changes
998b2045 Merge pull request contiki-ng#105 from pjonsson/remove-unused-imports
7a85907a Merge pull request contiki-ng#107 from pjonsson/remove-parens
a075b102 Remove superfluous parentheses
0fb692ae Remove unused variables/initalizations
a992585b Remove unused imports
eed48b1a Update mspsim submodule