REORG: listener: move the listening address to a struct receiver

The address will be specific to the receiver so let's move it there.
diff --git a/src/cfgparse.c b/src/cfgparse.c
index cc787b2..cc5f9f7 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -635,7 +635,7 @@
 					goto out;
 				}
 			}
-			newpeer->addr = l->addr;
+			newpeer->addr = l->rx.addr;
 			newpeer->proto = protocol_by_family(newpeer->addr.ss_family);
 			cur_arg++;
 		}