Use HTTP

Signed-off-by: Shizuo Fujita <fujita@clear-code.com>

Author: Watson1978

example/fluentd/fluent.conf

@@ -19,13 +19,14 @@
     chunk_limit_size 1m
   </buffer>
 
-  <grpc>
-    endpoint "collector:4317"
-  </grpc>
+  # Experimental
+  # <grpc>
+  #   endpoint "collector:4317"
+  # </grpc>
 
-  # <http>
-  #   endpoint "http://collector:4318"
-  # </http>
+  <http>
+    endpoint "http://collector:4318"
+  </http>
 </match>
 
 # Send traditional log messages to OpenTelemetry Collector using Fluentd Forward Protocol