Change ':' non-associativity example to fit better in line

Considering that there's a binary range operator expression, I think this variant should work just as fine as the old one.

chapters/operatorsandexpressions.tex

@@ -104,7 +104,7 @@ \section{Operator Precedence and Associativity}\label{operator-precedence-and-as
 Non-associative exponentiation and array range operator:
 \begin{lstlisting}[language=modelica]
 x ^ y ^ z     // Not legal, use parentheses to make it clear.
-a:b:c:d:e:f:g // Not legal, and scalar arguments gives no legal interpretation.
+a : b : c : d // Not legal, and scalar arguments gives no legal interpretation.
 \end{lstlisting}
 \end{nonnormative}