Postpone Clang on PPC

There is an issue with libclang-common-dev [0]

[0]: should be on https://lists.debian.org/debian-powerpc/2019/02/

.travis.yml

@@ -35,15 +35,6 @@ matrix:
         - docker run --rm --privileged multiarch/qemu-user-static:register --reset
         - docker run --rm -v `pwd`:`pwd` -w `pwd` "pqclean/debian-unstable-ppc" /bin/bash -c "uname -a &&
           make ${MAKETARGET}"
-    - name: "Run tests on qemu-ppc (Clang)"
-      os: linux
-      services: docker
-      env:
-        - MAKETARGET="run-functest-all run-testvectors-all run-sanitizer-all run-symbol-namespace-all"
-      script:
-        - docker run --rm --privileged multiarch/qemu-user-static:register --reset
-        - docker run --rm -v `pwd`:`pwd` -w `pwd` "pqclean/debian-unstable-ppc" /bin/bash -c "uname -a &&
-          make CC=clang ${MAKETARGET}"
     - name: "MacOS + Clang"
       os: osx
       osx_image: xcode10.1