[470246] Change sys tree print output on USR2.

Thanks to Yun Wu.

Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=470246

ChangeLog.txt

@@ -20,6 +20,8 @@ Broker:
 - Add systemd startup notification and services. Closes #471053.
 - Reduce unnecessary malloc and memcpy when receiving a message and storing
   it. Closes #470258.
+- Change sys tree printing output. This format shouldn't be relied upon and
+  may change at any time. Closes #470246.
 
 Client library:
 - Outgoing messages with QoS>1 are no longer retried after a timeout period.

src/subs.c

@@ -599,7 +599,8 @@ void sub__tree_print(struct mosquitto__subhier *root, int level)
 	struct mosquitto__subhier *branch;
 	struct mosquitto__subleaf *leaf;
 
-	for(i=0; i<level*2; i++){
+	if(level > 1){
+		for(i=0; i<(level-2)*2; i++){
 			printf(" ");
 		}
 		printf("%s", UHPA_ACCESS_TOPIC(root));
@@ -616,6 +617,7 @@ void sub__tree_print(struct mosquitto__subhier *root, int level)
 			printf(" (r)");
 		}
 		printf("\n");
+	}
 
 	branch = root->children;
 	while(branch){