Fixed robusta-cli old docs page redirection

Author: itisallgood

docs/conf.py

@@ -170,7 +170,7 @@
     "developer-guide/platform/coding-conventions.html": "/master/contributing.html",
     "developer-guide/platform/docs-contributions.html": "/master/docs-contributions.html#improving-these-docs",
     "developer-guide/platform/sinks-guide.html": "/master/configuration/sinks/sinks-development.html",
-    "user-guide/robusta-cli.html": "master/setup-robusta/installation/index.html"
+    "user-guide/robusta-cli.html": "/master/setup-robusta/installation/index.html"
 }