core.fsyncmethod: correctly camel-case warning message

The warning for an unrecognized fsyncMethod was not
camel-cased.

Reported-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

config.c

@@ -1694,7 +1694,7 @@ static int git_default_core_config(const char *var, const char *value, void *cb)
 
 	if (!strcmp(var, "core.fsyncobjectfiles")) {
 		if (fsync_object_files < 0)
-			warning(_("core.fsyncobjectfiles is deprecated; use core.fsync instead"));
+			warning(_("core.fsyncObjectFiles is deprecated; use core.fsync instead"));
 		fsync_object_files = git_config_bool(var, value);
 		return 0;
 	}