dont retransmit on reliable transports

git-svn-id: http://svn.berlios.de/svnroot/repos/sipsak/trunk@407 75b5f7c7-cfd4-0310-b54c-e118b2c5249a
(cherry picked from commit ca5bc7a2536d9b78f226ac95a4f4075569c3f37c)

shoot.c

@@ -1035,6 +1035,9 @@ void shoot(char *buf, int buff_size)
 				} /* redirect, auth, and modes */
 			} /* ret > 0 */
 			else if (ret == -1) { // we did not got anything back, send again
+				if (transport != SIP_UDP_TRANSPORT) {
+					cdata.dontsend = 1;
+				}
 				continue;
 			}
 			else if (ret == -2) { // we received non-matching ICMP