ipaccess: release virtual E1 line for closed connection

We fix a leak in the ipaccess_drop(...) path where we were missing
the release of the cloned E1 line for this OML/RSL links
diff --git a/src/input/ipaccess.c b/src/input/ipaccess.c
index a024054..5ecd2e6 100644
--- a/src/input/ipaccess.c
+++ b/src/input/ipaccess.c
@@ -242,6 +242,9 @@
 		bfd->fd = -1;
 		talloc_free(bfd);
 	}
+	/* release the virtual E1 line that we cloned for this socket,
+	 * OML and RSL links should have been closed after sign_link_down. */
+	talloc_free(line);
 }
 
 static int ipaccess_rcvmsg(struct e1inp_line *line, struct msgb *msg,