Spin for connection success also when socket is not (yet) available

We were spinning for socket connection if attempt to connect returned errno 111
(connection refused). However, it is not enough for local AF_UNIX sockets as
heavy applications might not be able to start yet and therefore the whole path
might be missing. So spin for errno 2 (no such file or directory) as well.

Partial fix for
  https://fedorahosted.org/freeipa/ticket/1990

ipaserver/install/installutils.py

@@ -508,7 +508,7 @@ def wait_for_open_socket(socket_name, timeout=0):
             s.close()
             break;
         except socket.error, e:
-            if e.errno == 111:  # 111: Connection refused
+            if e.errno in (2,111):  # 111: Connection refused, 2: File not found
                 if timeout and time.time() > op_timeout: # timeout exceeded
                     raise e
                 time.sleep(1)