Re-add a space to the expected output of the zipper.chpl spec test

It was accidentally removed with #4703, leading to the spec test to fail

Author: ronawho

Diff for: spec/Statements.tex

@@ -569,7 +569,7 @@ \subsection{Zipper Iteration}
 \end{chapelpost}
 is
 \begin{chapelprintoutput}{}
-1 4 2 5 3 6
+1 4 2 5 3 6 
 \end{chapelprintoutput}
 \end{chapelexample}