plugin: add small comment warning

License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protonmail.ch>

plugin/loader/Rules.mk

 include mk/header.mk
 
 $(d)/preload.go: d:=$(d)
-$(d)/preload.go: $(d)/preload_list
+$(d)/preload.go: $(d)/preload_list $(d)/preload.sh
 	$(d)/preload.sh > $@
 	go fmt $@ >/dev/null
 

plugin/loader/preload.sh

@@ -20,6 +20,11 @@ done | sort -u
 cat <<EOL
 )
 
+
+// DO NOT EDIT THIS FILE
+// This file is being generated as part of plugin build process
+// To change it, modify the plugin/loader/preload.sh
+
 var preloadPlugins = []plugin.Plugin{
 EOL