diff.c: diff.renamelimit => diff.renameLimit in message

In the warning message printed when rename or unmodified copy
detection was skipped due to too many files, change "diff.renamelimit"
to "diff.renameLimit", in order to make it consistent with git
documentation, which consistently uses "diff.renameLimit".

Signed-off-by: Max Nanasy <max.nanasy@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.c

@@ -4662,7 +4662,7 @@ int diff_result_code(struct diff_options *opt, int status)
 {
 	int result = 0;
 
-	diff_warn_rename_limit("diff.renamelimit",
+	diff_warn_rename_limit("diff.renameLimit",
 			       opt->needed_rename_limit,
 			       opt->degraded_cc_to_c);
 	if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&