Remove impact of case-fold-search on LaTeX class setup

* lisp/org-exp.el (org-infile-export-plist): Bind case-fold-search to t.

lisp/org-exp.el

@@ -695,6 +695,7 @@ modified) list.")
 		    "EXPORT_SELECT_TAGS" "EXPORT_EXCLUDE_TAGS"
 		    "KEYWORDS" "DESCRIPTION" "MACRO" "BIND" "XSLT")
 		  (mapcar 'car org-export-inbuffer-options-extra))))
+	    (case-fold-search t)
 	    p key val text options mathjax a pr style
 	    latex-header latex-class macros letbind
 	    ext-setup-or-nil setup-contents (start 0))