Revert "Wrap the node info to metadata in the Access Log Protocol (#93)" (#94)

This reverts commit cc8aa8ca4ee53a44487982a55762f72825824d73.
diff --git a/ebpf/accesslog.proto b/ebpf/accesslog.proto
index de5477f..324094b 100644
--- a/ebpf/accesslog.proto
+++ b/ebpf/accesslog.proto
@@ -32,8 +32,8 @@
 }
 
 message EBPFAccessLogMessage {
-    // metadata of access log, only not null when first message
-    EBPFAccessLogMetadata metadata = 1;
+    // current node information, only not null when first message or have update
+    EBPFAccessLogNodeInfo node = 1;
     // local process and remote process connection information
     AccessLogConnection connection = 2;
     // kernel level metrics
@@ -44,18 +44,6 @@
     AccessLogProtocolLogs protocolLog = 4;
 }
 
-message EBPFAccessLogMetadata {
-    // current node information
-    EBPFAccessLogNodeInfo node = 1;
-    // policy for access logs
-    EBPFAccessLogPolicy policy = 2;
-}
-
-message EBPFAccessLogPolicy {
-    // which namespaces should be excluded to generate the connection
-    repeated string excludeNamespaces = 1;
-}
-
 message EBPFAccessLogNodeInfo {
     // Node name
     string name = 1;