console: do not try to prevent SIGPIPE in text console

Text console tried to learn about SIGPIPE before its raising
by read-before-write. If a socket is readable, but read returns
0, then it is closed, and writing to it can raise SIGPIPE. But
Tarantool ignores SIGPIPE, so the process will not be terminated,
write() just returns -1.

The original code checks for SIGPIPE, because when Tarantool is
run under debugger (gdb or lldb), the debugger by default sets
its own signal handlers, and SIGPIPE terminates the process.

But debugger settings can be changed to ignore SIGPIPE too, so
lets remove this overengineering from the console code.