lightningd/plugin_control: don't control non-dynamic plugins

tests/plugins/static.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+"""Simple plugin to test the dynamic behavior.
+
+A plugin started with dynamic to False cannot be controlled after lightningd
+has been started.
+"""
+
+from lightning import Plugin
+
+plugin = Plugin(dynamic=False)
+
+
+@plugin.init()
+def init(configuration, options, plugin):
+    plugin.log("Static plugin initialized.")
+
+
+@plugin.method('hello')
+def reject(plugin):
+    """Mark a given node_id as reject for future connections.
+    """
+    return "Hello, you cannot stop me without stopping lightningd"
+
+
+plugin.run()