Ignore SIGPIPE

When the child process in tests/_client.lua breaks and exits (for
example: Remove the call to Gtk.main), we get a broken pipe. When trying
to write to the pipe that connects awesome to the child process, we get
a SIGPIPE signal that causes awesome to exit without any good error
message.

Fix this by ignoring SIGPIPE. We do not want to be killed by it anyway.

Signed-off-by: Uli Schlachter <psychon@znc.in>

awesome.c

@@ -575,6 +575,7 @@ main(int argc, char **argv)
     sigaction(SIGFPE, &sa, 0);
     sigaction(SIGILL, &sa, 0);
     sigaction(SIGSEGV, &sa, 0);
+    signal(SIGPIPE, SIG_IGN);
 
     /* We have no clue where the input focus is right now */
     globalconf.focus.need_update = true;