Don't establish RSL at same time as OML link on IPA type lines

If we have a BTS-side e1inp_line, we can only establish OML at the
time of line_update.  We have to wait with RSL until the BTS explicitly
tells us the RSL destination IP and port (received via OML from BSC).

This is now handled in a new function called
e1inp_ipa_bts_rsl_connect().
diff --git a/tests/e1inp_ipa_bts_test.c b/tests/e1inp_ipa_bts_test.c
index 31aac95..02a4cb3 100644
--- a/tests/e1inp_ipa_bts_test.c
+++ b/tests/e1inp_ipa_bts_test.c
@@ -70,6 +70,7 @@
 			/* Now we can send OML messages to the BSC. */
 			bts_state = BTS_TEST_OML_SIGN_LINK_UP;
 		}
+		e1inp_ipa_bts_rsl_connect(line, "127.0.0.1", IPA_TCP_PORT_RSL);
 		break;
 	case E1INP_SIGN_RSL:
 		LOGP(DBTSTEST, LOGL_NOTICE, "RSL link up request received.\n");