BUG/MINOR: server: fix the format of the warning on address change

When the server address is changed, a message with unrequired '\n' or
'.' is displayed, like this:

   [WARNING] 054/101137 (3229) : zzzz/s3 changed its IP from 127.0.0.1 to ::55 by stats command
   .

This patch remove the '\n' which is sent before the '.'.

This patch must be backported in 1.6
diff --git a/src/server.c b/src/server.c
index 30722fc..cd32e80 100644
--- a/src/server.c
+++ b/src/server.c
@@ -819,11 +819,11 @@
 	unsigned char ip[INET6_ADDRSTRLEN];
 
 	if (inet_pton(AF_INET6, addr_str, ip)) {
-		update_server_addr(sv, ip, AF_INET6, "stats command\n");
+		update_server_addr(sv, ip, AF_INET6, "stats command");
 		return NULL;
 	}
 	if (inet_pton(AF_INET, addr_str, ip)) {
-		update_server_addr(sv, ip, AF_INET, "stats command\n");
+		update_server_addr(sv, ip, AF_INET, "stats command");
 		return NULL;
 	}