Fixed index references to modules.

Doc/lib/libsite.tex

@@ -78,7 +78,7 @@ After these path manipulations, an attempt is made to import a module
 named \code{sitecustomize}, which can perform arbitrary site-specific
 customizations.  If this import fails with an \code{ImportError}
 exception, it is silently ignored.
-\stmodindex{sitecustomize}
+\refmodindex{sitecustomize}
 
 Note that for some non-Unix systems, \code{sys.prefix} and
 \code{sys.exec_prefix} are empty, and the path manipulations are

Doc/libsite.tex

@@ -78,7 +78,7 @@ After these path manipulations, an attempt is made to import a module
 named \code{sitecustomize}, which can perform arbitrary site-specific
 customizations.  If this import fails with an \code{ImportError}
 exception, it is silently ignored.
-\stmodindex{sitecustomize}
+\refmodindex{sitecustomize}
 
 Note that for some non-Unix systems, \code{sys.prefix} and
 \code{sys.exec_prefix} are empty, and the path manipulations are