Remove an outdated sentence from chapter 16

PR elixir-lang#421 moved the try/catch/rescue chapter to chapter 19 (it was chapter 17
before), but the last sentence of chapter 16 still mentioned that in the next
chapter errors would be covered. That is not true anymore.

Author: whatyouhide

getting_started/16.markdown

@@ -195,4 +195,4 @@ iex> inspect &(&1+2)
 "#Function<6.71889879/1 in :erl_eval.expr/5>"
 ```
 
-There are other protocols in Elixir but this covers the most common ones. In the next chapter we will learn a bit more about error handling and exceptions in Elixir.
+There are other protocols in Elixir but this covers the most common ones.