Remove LaTeX source comment replaced by modelica#2510

chapters/classes.tex

@@ -1056,7 +1056,6 @@ \section{Balanced Models}\doublelabel{balanced-models}
 \end{itemize}
 
 The following restrictions hold:
-
 \begin{itemize}
 \item
   In a non-partial model or block, all non-connector inputs of model or
@@ -1216,7 +1215,6 @@ \section{Balanced Models}\doublelabel{balanced-models}
 any guarantees for the global set of equations, and specific
 combinations of models that are locally non-singular may lead to a
 globally non-singular model.}{]}
-% The sentence above looks strange.  Shouldn't it be "globally singular"?
 
 \emph{Example 3:}
 \begin{lstlisting}[language=modelica]