chore(logging): default to multi-line logging

etc/emqx.conf

@@ -446,7 +446,7 @@ log.file = emqx.log
 
 ## Log to single line
 ## Value: boolean
-#log.single_line = true
+#log.single_line = false
 
 ## Enables the log rotation.
 ## With this enabled, new log files will be created when the current

priv/emqx.schema

@@ -487,7 +487,7 @@ end}.
 
 %% @doc format logs in a single line.
 {mapping, "log.single_line", "kernel.logger", [
-  {default, true},
+  {default, false},
   {datatype, {enum, [true, false]}}
 ]}.
 

src/emqx_tracer.erl

@@ -42,7 +42,7 @@
                               [peername, " "],
                               []}]},
                        msg, "\n"],
-                    single_line => true
+                    single_line => false
                    }}).
 -define(TOPIC_TRACE_ID(T), "trace_topic_"++T).
 -define(CLIENT_TRACE_ID(C), "trace_clientid_"++C).