gazebo is marked for autoremoval from testing

[Debian testing autoremoval watch]

gazebo 9.0.0+dfsg5-4.1 is marked for autoremoval from testing on 2018-09-08

It is affected by these RC bugs:
893408: gazebo: Please use clang-format insteal of clang-format-4.0

It (build-)depends on packages with these RC bugs:
891690: libclang-common-4.0-dev: /usr/lib/llvm-4.0/lib/clang/4.0.1/lib/ is empty on mipsel
897804: llvm-toolchain-4.0: ftbfs with GCC-8
906230: insighttoolkit4-python: missing python dependencies