tutorial: Remove disclaimer. Redundant with previous section

Author: brson

doc/tutorial.md

@@ -138,14 +138,6 @@ they don't contain references to things that aren't actually defined.
 > about potential changes to the language, implementation
 > deficiencies, and other caveats appear offset in blockquotes.
 
-## Disclaimer
-
-Rust is a language under development. The general flavor of the
-language has settled, but details will continue to change as it is
-further refined. Nothing in this tutorial is final, and though we try
-to keep it updated, it is possible that the text occasionally does not
-reflect the actual state of the language.
-
 # Getting started
 
 ## Installation