Fix handling of SIGPIPE

[marki555]

Right now rtl_433 cannot handle SIGPIPE properly - it goes into endless loop caused by fprintf command inside the sighandler() function (each subsequent fprintf creates another SIGPIPE signal).
The fix is easy (I don't know how to create a pull request here), just add this line at the beginning of sighandler() function in rtl_433.c:

   if (signum == SIGPIPE) signal(SIGPIPE, SIG_IGN);

[zerog2k]

+1 having this problem too. I think this patches it, at least for linux side. (Cant test windows.)

You can fork this repo, create a feature branch on that repo for the fix, push that back to your repo, and there should be a pull request option when you visit this repo.
https://help.github.com/articles/creating-a-pull-request