Added #ifndef around NGX_HAVE_CASELESS_FILESYSTEM define.
This brings Cygwin compilation in line with other case-insensitive
systems (notably win32 and OS X) where one can force case sensitivity
using -DNGX_HAVE_CASELESS_FILESYSTEM=0.
diff --git a/src/os/unix/ngx_files.h b/src/os/unix/ngx_files.h
index 4b20165..a78ec96 100644
--- a/src/os/unix/ngx_files.h
+++ b/src/os/unix/ngx_files.h
@@ -53,7 +53,9 @@
#ifdef __CYGWIN__
+#ifndef NGX_HAVE_CASELESS_FILESYSTEM
#define NGX_HAVE_CASELESS_FILESYSTEM 1
+#endif
#define ngx_open_file(name, mode, create, access) \
open((const char *) name, mode|create|O_BINARY, access)