add unregister_on_exit (#1020)

* add unregister_on_exit

Author: sabban

crowdsec-docs/docs/configuration/values_parameters.md

@@ -138,9 +138,12 @@ lapi:
 
 config:
   config.yaml.local: |
-    # This is needed for agent autoregistration
     api:
+      client:
+        # the log processor will remove delete itself from LAPI when stopping.    
+        unregister_on_exit: true
       server:
+        # This is needed for agent autoregistration
         auto_registration: # Activate if not using TLS for authentication
           enabled: true
           token: "${REGISTRATION_TOKEN}" # /!\ Do not modify this variable (auto-generated and handled by the chart)