COMP: Correct typo that made ITKSoftwareGuide compilation fail

Author: Francois Budin

SoftwareGuide/Latex/DevelopmentGuidelines/WriteAFilter.tex

@@ -335,7 +335,7 @@ \subsubsection{UpdateOutputInformation()}
 sources.
 
 After the upstream inputs have completed their
-\Code{UpdateOutputInformation} the metadata of inputs are
+\code{UpdateOutputInformation} the metadata of inputs are
 available. The \code{VerifyInputInformation} is then called. The
 default implementation in \code{ImageToImageFilter} checks that all
 input images occupy the same physical space. This may need to be