textproc/scim-bridge: Mark as broken on systems using Clang 6

scim-bridge-agent-signal-listener.cpp:67:9: error: no matching function for call to 'send'

send (pipe_in, '\0', sizeof (char), MSG_NOSIGNAL);
^~~~

/usr/include/sys/socket.h:680:9: note: candidate function not viable: no known conversion from 'char' to 'const void *' for 2nd argument
ssize_t send(int, const void *, size_t, int);

^

There was no maintainer feedback and it is doubtful that my proposed
fix in the PR is correct.

PR: 230891